Technical information

GARBA

Precipitation hardenable stainless spring wire.
For applications demanding medium fatigue properties.

GARBA 177PH is a semi-austenitic precipitation-hardenable stainless steel with high relaxation resistance at elevated temperatures and excellent fatigue properties. This material has good formability and good form stability during the precipitation hardening heat treatment and a moderate level of corrosion resistance.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Al (%)	Ni (%)
0.09	0.70	1.00	0.040	0.015	16.00 - 18.00	0.70 - 1.50	6.50 - 7.80

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Tensile strength after heat treatment 480C 1h (N/mm²)
0.30 - 0.65	±0.005	-	-
0.66 - 1.01	±0.008	-	-
1.02 - 2.26	±0.012	-	-
2.27 - 4.01	±0.015	-	-
4.02 - 6.26	±0.020	-	-
6.27 - 8.00	±0.025	-	-
0.30 - 0.40		1925 - 2213	2225 - 2525
0.41 - 0.50		1900 - 2185	2200 - 2500
0.51 - 0.65		1850 - 2127	2150 - 2450
0.66 - 0.80		1825 - 2099	2125 - 2425
0.81 - 1.00		1800 - 2070	2100 - 2400
1.01 - 1.25		1750 - 2012	2050 - 2350
1.26 - 1.50		1700 - 1955	2000 - 2300
1.51 - 1.75		1650 - 1897	1950 - 2250
1.76 - 2.00		1600 - 1840	1900 - 2200
2.01 - 2.50		1550 - 1782	1850 - 2150
2.51 - 3.00		1500 - 1725	1800 - 2100
3.01 - 3.50		1450 - 1667	1750 - 2050
3.51 - 4.25		1400 - 1610	1700 - 2000
4.26 - 5.00		1350 - 1552	1650 - 1950
5.01 - 6.00		1300 - 1495	1550 - 1850
6.01 - 8.00		1250 - 1437	1500 - 1800

Surface conditions

Surface performance
AC-surface 0.30–8.00 mm Ø.
The AC-coating can be removed before heat treatment by using a 10-20% nitric acid pickle at room temperature.

Physical properties

E and G modulus of elasticity

Abt. 190 kN/mm² in drawn condition.
Abt. 200 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 73 kN/mm² in drawn condition.
Abt. 78 kN/mm² after heat treatment.

Heat conductivity

Temperature ^oC	20	100	300
W/(m* ^oC)	15.0	15.5	19.0

Resistivity

Temperature ^oC	20	100	200	300
nΩm	900	950	1000	1050

Linear expansion

Pro ^oC	<30-100	30-200	30-300
x10^-6	13.0	13.5	14.0

Specific heat capactity

Temperature ^oC	100	200
J/(kg* ^oC)	480	520

Standards

Nearest equivalent steel grades

EN/DIN 1.4568, AISI/SAE 631, JIS SUS 631

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, AMS 5678, BS 2056 301 S81, JIS G4314

Recommendations

Heat treatment

Normal procedure for precipitation hardening is heat treatment at 480^oC (896^oF) for 1 hour and then air cooling. This should be done as soon as possible after spring coiling. The tensile strength of the wire before and after this treatment is given in the table in previous page.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

Shot peening of the inside of the spring coils is particularly critical.

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of GARBA 177 PH is illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2-3 show the relaxation properties (loss of load) of springs made from GARBA 177PH subjected to three different stress levels at different temperatures.

GARBA 177 Premium

Precipitation hardenable stainless spring wire. Shaved and EC-tested *)
For applications demanding high fatigue properties

GARBA 177 Premium is a semi-austenitic precipitation-hardenable stainless steel with high relaxation resistance at elevated temperatures and excellent fatigue properties. This material has good formability and good form stability during the precipitation hardening heat treatment and a moderate level of corrosion resistance. The shaved surface improves the fatigue resistance as compared to GARBA 177PH.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)	Al (%)
0.09	0.70	1.00	0.040	0.015	16.00 - 18.00	6.50 - 7.80	0.70 - 1.50

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Tensile strength after heat treatment 480C 1h (N/mm²)
0.30 - 0.40	±0.005	1885 - 2165	2205 - 2525
0.41 - 0.50	±0.008	1860 - 2130	2180 - 2490
0.51 - 0.65	±0.008	1810 - 2070	2130 - 2430
0.66 - 0.80	±0.010	1810 - 2060	2130 - 2430
0.81 - 1.00	±0.010	1780 - 2030	2100 - 2390
1.01 - 1.25	±0.015	1720 - 1960	2040 - 2310
1.26 - 1.50	±0.015	1670 - 1910	1990 - 2260
1.51 - 1.75	±0.015	1610 - 1850	1910 - 2180
1.76 - 2.00	±0.015	1570 - 1800	1900 - 2160
2.01 - 2.50	±0.015	1540 - 1770	1860 - 2120
2.51 - 3.00	±0.020	1500 - 1710	1820 - 2060
3.01 - 3.50	±0.020	1400 - 1600	1660 - 1940
3.51 - 4.25	±0.020	1350 - 1550	1620 - 1920
4.26 - 5.00	±0.025	1310 - 1500	1580 - 1800
5.01 - 5.60	±0.025	1300 - 1490	1550 - 1790

Surface conditions

Surface performance
AC-surface 0.30–5.60 mm Ø. The AC-coating can be removed before heat treatment by using a 10-20% nitric acid pickle at room temperature.

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00-5,60 mm the wire can be tested continuously in Eddy Current equipment to a surface level of >40 microns.

Physical properties

E and G modulus of elasticity

Abt. 190 kN/mm² in drawn condition.
Abt. 200 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 73 kN/mm² in drawn condition.
Abt. 78 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Heat conductivity

Temperature ^oC	20	100	300
W/(m* ^oC)	15.0	15.5	19.0

Linear expansion

Pro ^oC	30-100	30-200	30-300
x10^-6	13.0	13.5	14.0

Standards

Nearest equivalent steel grades

EN/DIN 1.4568, AISI/SAE 631, JIS SUS 631

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, AMS 5678, BS 2056 301 S81, JIS G4314

Recommendations

Heat treatment

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.
Shot peening of the inside of the spring coils is particularly critical.

GARBA 177 Supreme

Precipitation hardenable stainless spring wire. Shaved and EC-tested*. For applications demanding superior fatigue properties

GARBA 177 Supreme® is a semi-austenitic precipitation-hardenable stain¬less steel, processed by ESR (Electro Slag Refining), which reduces the risk of harmful inclusions. The ESR process together with a shaved surface improves the fatigue resistance as compared to GARBA 177PH.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)	Al (%)
0.09	0.70	1.00	0.040	0.015	16.00 - 18.00	6.50 - 7.80	0.70 - 1.50

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is
inspected for every heat in accordance with the Suzuki
Garphyttan method by the steel supplier.

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 350 mm².

Inclusion size, surface	5–10	> 10–15	>15 µm
Max. number of inclusions	Max grade D3 acc. to JK scale*	20	0

* Method for assessment of the content of non-metallic inclusions. Swedish Standard SS 111116 – Microscopic methods – Jernkontoret’s inclusion chart II for the assessment of non-metallic inclusions.

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Tensile strength after heat treatment 480C 1h (N/mm²)
0.30 - 0.40	±0.005	1885 - 2165	2205 - 2525
0.41 - 0.50	±0.008	1860 - 2130	2180 - 2490
0.51 - 0.65	±0.008	1810 - 2070	2130 - 2430
0.66 - 0.80	±0.010	1810 - 2060	2130 - 2430
0.81 - 1.00	±0.010	1780 - 2030	2100 - 2390
1.01 - 1.25	±0.015	1720 - 1960	2040 - 2310
1.26 - 1.50	±0.015	1670 - 1910	1990 - 2260
1.51 - 1.75	±0.015	1610 - 1850	1910 - 2180
1.76 - 2.00	±0.015	1570 - 1800	1900 - 2160
2.01 - 2.50	±0.015	1540 - 1770	1860 - 2120
2.51 - 3.00	±0.020	1500 - 1710	1820 - 2060
3.01 - 3.50	±0.020	1400 - 1600	1660 - 1940
3.51 - 4.25	±0.020	1350 - 1550	1620 - 1920
4.26 - 5.00	±0.025	1310 - 1500	1580 - 1800
5.01 - 5.60	±0.025	1300 - 1490	1550 - 1790

Surface conditions

Surface performance
AC-surface 0.30–5.60 mm Ø . The AC-coating can be removed before heat treatment by using a 10-20% nitric acid pickle at room temperature.

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00-5,60 mm the wire can be tested continuously in Eddy Current equipment to a surface level of >40 microns.

Physical properties

E and G modulus of elasticity

Abt. 190 kN/mm² in drawn condition.
Abt. 200 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 73 kN/mm² in drawn condition.
Abt. 78 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Heat conductivity

Temperature ^oC	20	100	300
W/(m* ^oC)	15.0	15.5	19.0

Resistivity

Temperature ºC	20	100	200	300
nΩm	900	950	1000	1050

Linear expansion

Pro ^oC	30-100	30-200	30-300
x10^-6	13.0	13.5	14.0

Specific heat capactity

Temperature ^oC	100	200
J/(kg* ^oC)	480	520

Standards

Nearest equivalent steel grades

EN/DIN 1.4568, AISI/SAE 631, JIS SUS 631

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, AMS 5678, BS 2056 301 S81, JIS G4314

Recommendations

Electro slag refining (ESR) process
For applications demanding superior fatigue properties

Electro Slag Refining (ESR) process
ESR process, see figure 1.
The ESR process gives a material with lower level of inclusions compared to a material not processed with ESR and in addition also a better segregation level.
Material properties achieved by ESR in combination with shaved wire surface and precipitation hardening result in superior fatigue resistance.

Shaved and Eddy Current tested

Suzuki Garphyttan uses the most advanced Eddy Current testing equip¬ment available on the market. Experience from many years of surface testing in efficient continuous testing lines is a guarantee for high quality spring wire.

Eddy Current testing is carried out on material with high demands on surface quality. EC-testing is performed with both rotating (R) and stationary (D) probe test equipment.

Steel grade	Dimension, mm	ESR	Shaved	Unshaved	RD40
GARBA 177 Supreme®	0.30 – 1.99	x	x	-	-
GARBA 177 Supreme®	2.00 – 5.60	x	x	-	x

Steel grade Dimension, mm ESR Shaved Unshaved RD40
GARBA 177 Supreme® 0.30 – 1.99 X X – –
GARBA 177 Supreme® 2.00 – 5.60 X X – X

Heat treatment

Normal procedure for precipitation hardening is heat treatment at 480oC (896oF) for 1 hour and then air cooling. This should be done as soon as possible after spring coiling. The tensile strength of the wire before and after this treatment is given in the table in previous page.

Shot peening

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of GARBA 177 Supreme® is illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2-3 show the relaxation properties (loss of load) of springs made from GARBA 177 Supreme® subjected to three different stress levels at different temperatures.

GARBA 178Mo

Stainless spring wire. Similar to EN 1.4310 with increased tensile strength

GARBA 178Mo is a general-purpose austenitic stainless steel that is used for springs and other components requiring good fatigue resistance and good resistance against atmospheric corrosion. Addition of molybdenum increases the tensile strength as compared to GARBA 188 and also increases the resistance against localised and general corrosion.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)	Mo (%)
0.05 - 0.15	2.00	2.00	0.045	0.015	16.00 - 19.00	6.00 - 9.50	0.80

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)
0.30 - 0.65	±0.008	-
0.66 - 1.01	±0.010	-
1.02 - 2.26	±0.015	-
2.27 - 4.01	±0.020	-
4.02 - 6.26	±0.025	-
6.27 - 8.00	±0.030	-
0.30 - 0.40		2250 - 2590
0.41 - 0.50		2200 - 2530
0.51 - 0.65		2150 - 2470
0.66 - 0.80		2100 - 2420
0.81 - 1.00		2050 - 2360
1.01 - 1.25		2000 - 2300
1.26 - 1.50		1950 - 2240
1.51 - 1.75		1900 - 2190
1.76 - 2.00		1850 - 2130
2.01 - 2.50		1750 - 2010
2.51 - 3.00		1700 - 1960
3.01 - 3.50		1650 - 1900
3.51 - 4.25		1600 - 1840
4.26 - 5.00		1550 - 1780
5.01 - 6.00		1500 - 1730
6.01 - 7.00		1450 - 1670
7.01 - 8.00		1400 - 1610

Surface conditions

Surface performance
AC-surface 0.30–8.00 mm Ø. The AC-coating can be removed before heat treatment by using a 10-20% nitric acid pickle at room temperature.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm² in drawn condition.
Abt. 185 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.

Heat conductivity

Temperature °C	20	100	200	400
W/(m* °C)	15.0	16.0	18.0	20.0

Resistivity

Temperature ^oC	20	100	200	300
nΩm	700	750	800	950

Linear expansion

Pro °C	30–100	30–200	30–400
x10 ^–6	17.0	17.5	18.5

Specific heat capactity

Temperature ^oC	20	100	200	400
J/(kg* ^oC)	440	480	520	560

Standards

Nearest equivalent steel grades

EN/DIN 1.4310, AISI/SAE 302

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, BS 2056 302 S26

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.
Recommended temperature for compression springs or tension springs without initial tension is approx. 420 ºC for 0.5 - 4 hours.

GARBA 1812Mo

Stainless spring wire

GARBA 1812Mo is an austenitic stainless steel, which as compared to GARBA 178Mo offers a higher resistance against intergranular corrosion due to lower carbon content. The higher content of molybdenum also increases the resistance against general corrosion.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)	Mo (%)
0.07	1.00	2.00	0.045	0.015	16.50 - 18.50	10.00 - 13.00	2.00 - 3.00

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)
0.30 - 0.65	±0.008	-
0.66 - 1.01	±0.010	-
1.02 - 2.26	±0.015	-
2.27 - 4.01	±0.020	-
4.02 - 6.26	±0.025	-
6.27 - 8.00	±0.030	-
0.30 - 0.40		1675 - 1930
0.41 - 0.50		1650 - 1900
0.51 - 0.65		1625 - 1870
0.66 - 0.80		1600 - 1840
0.81 - 1.00		1575 - 1810
1.01 - 1.25		1550 - 1780
1.26 - 1.50		1500 - 1730
1.51 - 1.75		1450 - 1670
1.76 - 2.00		1400 - 1610
2.01 - 2.50		1350 - 1550
2.51 - 3.00		1300 - 1500
3.01 - 3.50		1250 - 1440
3.51 - 4.25		1225 - 1410
4.26 - 5.00		1200 - 1380
5.01 - 6.00		1150 - 1320
6.01 - 7.00		1125 - 1290
7.01 - 8.00		1075 - 1240

Surface conditions

Surface performance
AC-surface 0.30–8.00 mm Ø. The AC-coating can be removed before heat treatment by using a 10-20% nitric acid pickle at room temperature.

Physical properties

E and G modulus of elasticity

Abt. 175 kN/mm² in drawn condition.
Abt. 180 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 68 kN/mm² in drawn condition.
Abt. 71 kN/mm² after heat treatment.
Density: 8.00 kg/dm³.

Heat conductivity

Temperature ^oC	20	100	200	400
W/(m*^oC)	13.5	14.5	15.5	18.5

Resistivity

Temperature ^oC	20	100	200	400
nΩm	750	800	850	1000

Linear expansion

Pro ^oC	30-100	30-200	30-400
x10^-6	16.5	17.0	18.0

Specific heat capactity

Temperature ^oC	20	100	200	400
J/(kg*^oC)	440	480	520	560

Standards

Nearest equivalent steel grades

EN/DIN 1.4401, AISI/SAE 316, JIS SUS 316

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, BS 2056 316 S42, JIS G4314

Recommendations

Heat treatment

GARBA 188

Stainless spring wire

GARBA 188 is a general-purpose austenitic stainless steel, which is used for springs and other components requiring good fatigue resistance. The formability is excellent and the corrosion resistance is good against atmospheric corrosion

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)
0.05 - 0.15	2.00	2.00	0.045	0.015	16.00 - 19.00	6.00 - 9.50

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)
0.30 - 0.65	±0.008	-
0.66 - 1.01	±0.010	-
1.02 - 2.26	±0.015	-
2.27 - 4.01	±0.020	-
4.02 - 6.26	±0.025	-
6.27 - 8.00	±0.030	-
0.30 - 0.30		2150 - 2470
0.31 - 0.40		2100 - 2420
0.41 - 0.50		2050 - 2360
0.51 - 0.65		2000 - 2300
0.66 - 0.80		1950 - 2240
0.81 - 1.00		1900 - 2190
1.01 - 1.25		1850 - 2130
1.26 - 1.50		1800 - 2070
1.51 - 1.75		1750 - 2010
1.76 - 2.00		1700 - 1960
2.01 - 2.50		1650 - 1900
2.51 - 3.00		1600 - 1840
3.01 - 3.50		1550 - 1780
3.51 - 4.25		1500 - 1730
4.26 - 5.00		1450 - 1670
5.01 - 6.00		1400 - 1610
6.01 - 7.00		1350 - 1550
7.01 - 8.00		1300 - 1500

Surface conditions

Surface performance
AC-surface 0.30–8.00 mm Ø. The AC-coating can be removed before heat treatment by using a 10-20% nitric acid pickle at room temperature.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm² in drawn condition.
Abt. 185 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Heat conductivity

Temperature ^oC	20	100	200	400
W/(m* ^oC)	15.0	15.5	17.5	20.0

Resistivity

Temperature ^oC	20	100	200	300
nΩm	700	750	800	950

Linear expansion

Pro ^oC	30-100	30-200	30-300
x10^-6	17.0	17.5	18.5

Specific heat capactity

Temperature ^oC	20	100	200	400
J/(kg* ^oC)	440	480	520	560

Standards

Nearest equivalent steel grades

EN/DIN 1.4310, AISI/SAE 302, JIS SUS 302

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, AMS 5688, BS 2056 302 S26, JIS G4314

Recommendations

Heat treatment

GARBA 188L

Stainless spring wire

GARBA 188 is a general-purpose austenitic stainless steel, which is used for springs and other components requiring good fatigue resistance. GARBA 188L has a higher formability as compared to GARBA 188 due to its lower carbon content.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)
0.08	1.00	2.00	0.040	0.015	18.00 - 20.00	8.50 - 10.00

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)
0.30 - 0.50	±0.005	-
0.51 - 0.70	±0.008	-
0.71 - 0.83	±0.009	-
0.84 - 1.00	±0.010	-
1.01 - 1.60	±0.011	-
1.61 - 2.50	±0.014	-
2.51 - 4.00	±0.018	-
4.01 - 6.30	±0.022	-
6.31 - 8.00	±0.028	-
0.30 - 0.40		1785 - 2000
0.41 - 0.70		1700 - 1910
0.71 - 1.00		1650 - 1830
1.01 - 1.50		1530 - 1740
1.51 - 2.00		1445 - 1650
2.01 - 2.80		1360 - 1570
2.81 - 4.00		1275 - 1490
4.01 - 6.00		1190 - 1400
6.01 - 8.00		1105 - 1320

Surface conditions

Surface performance
AC-surface 0.30–8.00 mm Ø. The AC-coating can be removed before heat treatment by using a 10-20% nitric acid pickle at room temperature.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm² in drawn condition.
Abt. 185 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Heat conductivity

Temperature ^oC	20	100	200	400
W/(m* ^oC)	15.0	15.5	17.5	20.0

Linear expansion

Pro ^oC	30-100	30-200	30-300
x10^-6	17.0	17.5	18.5

Standards

Nearest equivalent steel grades

EN/DIN 1.4301, AISI/SAE 304, JIS SUS 304

Nearest equivalent standards

ASTM A313, BS 2056 304 S15, JIS G4314

Recommendations

Heat treatment

GARBAFLEX

GARBAFLEX 11R51

Flat and shaped wire

GARBAFLEX 11R51 is an austenitic stainless steel wire alloyed with molybdenum, supplied in the cold rolled or annealed condition.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)	Mo (%)
0.07 - 0.09	1.20 - 1.80	1.50 - 2.00	0.025	0.010	16.00 - 18.00	7.00 - 8.50	0.50 - 0.80

Mechanical properties

Tensile strength
As cold rolled max. 2400 N/mm².
As annealed max. 850 N/mm².

For flat rolled wire

Width (mm)	Tolerance (mm)
1.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.30 - 0.80	±0.015
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.01	±0.060

Elongation

As annealed min. 40%.

Microstructure

Austenite.

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).

Camber

Max. 3 mm measured on 1 m length.

Surface conditions

Surface

Bright. Surface defects max. 1% of thickness.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm²in drawn condition.
Abt. 185 kN/mm²after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Standards

Nearest equivalent steel grades

EN/DIN 1.4310, AISI/SAE 302, JIS SUS 302

Nearest equivalent standards

EN ISO 6931-1, ISO 6931-1, ASTM A313

Additional

Additional information

Delivery form
On wooden spools, max. 250 kg.

GARBAFLEX 174Mn

Flat and shaped wire

GARBAFLEX 174Mn is an austenitic stainless wire, supplied in the cold rolled or annealed condition.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)
0.15	1.00	5.50 - 7.50	0.045	0.030	16.00 - 18.00	3.50 - 5.50

Mechanical properties

Tensile strength
As cold rolled max. 1900 N/mm².
As annealed max. 950 N/mm².

Yield strength
As annealed 300-450 N/mm².

For flat rolled wire

Width (mm)	Tolerance (mm)
2.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.30 - 0.80	±0.015
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.00	±0.060

Elongation

As annealed min. 40%.

Microstructure

Austenite.

Camber

Max. 5 mm measured on 1 m length.

Surface conditions

Surface

Bright. Surface defects max. 1% of thickness.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm² in drawn condition.
Abt. 185 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Standards

Nearest equivalent steel grades

EN/DIN 1.4371, AISI/SAE 201, JIS SUS 201

Nearest equivalent standards

JIS G4309

Additional

Additional information

Delivery form
On wooden spools. Max. 250 kg.

GARBAFLEX 177 PH

Flat and shaped wire

GARBAFLEX 177PH is a precipitation hardenable stainless wire for flat and shaped wire applications in corrosive atmos-phere and elevated working temperature.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)	Al (%)
0.09	0.70	1.00	0.025	0.015	16.00 - 18.00	6.50 - 7.80	0.70 - 1.50

Mechanical properties

For flat rolled wire

Width (mm)	Tolerance (mm)
1.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.30 - 0.80	±0.013
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025
1.61 - 2.30	±0.050

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.00	±0.060

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).

Surface conditions

Surface

Bright. Surface defects max. 1% of thickness.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm² in drawn condition.
Abt. 185 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Standards

Nearest equivalent steel grades

EN/DIN 1.4568, AISI/SAE 631, JIS SUS 631

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, AMS 5678 F, JIS G4314

Recommendations

Heat treatment

For best spring properties the springs are heat treated at a temperature of 480 ºC (896 ºF) for 1 hour and then air cooled. The tensile strength of the wire before and after this treatment is given in the table for steel grade GARBA 177PH.

GARBAFLEX 188

Flat and shaped wire

GARBAFLEX 188 is an austenitic stainless wire, supplied in the cold rolled or annealed condition.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)
0.08	2.00	2.00	0.045	0.015	16.00 - 19.00	6.00 - 9.50

Mechanical properties

Tensile strength
As cold rolled max. 1850 N/mm².
As annealed max. 850 N/mm².

For flat rolled wire

Width (mm)	Tolerance (mm)
2.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.20 - 0.80	±0.015
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.00	±0.060

Elongation

Min. 40%.

Microstructure

Austenite.

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).

Camber

Max. 5 mm measured on 1 m length.

Coil set

Max. 20 mm measured on 1 m length.

Surface conditions

Bright. Surface defects max. 1% of thickness.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm² in drawn condition.
Abt. 185 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Standards

Nearest equivalent steel grades

EN/DIN 1.4310, AISI/SAE 302, JIS SUS 302

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, AMS 5688, BS 2056 302 S25, JIS G4314

GARBAFLEX 188L

Flat and shaped wire

GARBAFLEX 188L is an austenitic stainless wire, supplied in the cold rolled or annealed condition.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	Ni (%)
0.09	1.00	2.00	0.040	0.015	18.00 - 20.00	8.50 - 10.00

Mechanical properties

Tensile strength
As cold rolled max. 1850 N/mm².
As annealed max. 850 N/mm².

For flat rolled wire

Width (mm)	Tolerance (mm)
2.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.20 - 0.80	±0.015
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.00	±0.060

Elongation

Min. 40%.

Microstructure

Austenite.

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).

Camber

Max. 5 mm measured on 1 m length.

Coil set

Max. 20 mm measured on 1 m length.

Surface conditions

Bright. Surface defects max. 1% of thickness.

Physical properties

E and G modulus of elasticity

Abt. 180 kN/mm² in drawn condition.
Abt. 185 kN/mm² after heat treatment.

E and G modulus of shear

Abt. 70 kN/mm² in drawn condition.
Abt. 73 kN/mm² after heat treatment.
Density: 7.90 kg/dm³.

Standards

Nearest equivalent steel grades

EN/DIN 1.4301, AISI/SAE 304, JIS SUS 304

Nearest equivalent standards

EN ISO 6931-1, ASTM A313, BS 2056 304 S15, JIS G4314

GARBAFLEX 75

Flat and shaped wire

GARBAFLEX 75 has a uniform microstructure of tempered martensite. A special heat treatment process has made it possible to produce a material sufficiently ductile for coiling on edge without fracture.

Chemical composition

C (%)	Si (%)	Mn (%)	Cr (%)	P max. (%)	S max. (%)
0.60 - 0.80	0.10 - 0.30	0.55 - 0.90	0.20	0.035	0.035

Mechanical properties

For flat rolled wire

Width (mm)	Tolerance (mm)
1.00 - 5.00	±0.050
5.01 - 8.01	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Hardness
0.30 - 0.80	±0.013	1720 - 1860	69 - 72 HR30N
0.81 - 1.00	±0.019	1720 - 1860	69 - 72 HR30N
1.01 - 1.60	±0.025	1480 - 1625	46 - 49 HRC
1.61 - 2.30	±0.050	1480 - 1625	46 - 49 HRC

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.01	±0.060

Microstructure

Tempered martensite with no ferrite.

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).
Profile drawn.

Camber

Max. 4 mm measured on 1 m length.

Surface conditions

Surface

White polished or oxide.
Surface defects max. 1% of thickness.

Physical properties

Density: 7.95 kg/dm³.

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN/DIN 1070, AISI/SAE 1070

Nearest equivalent standards

EN 10270-1

Additional

Additional information

Decarburization
No total decarburisation. Partial decarburisation (no continuous zones) max. 1.2% of a corresponding round wire dimension.

GARBAFLEX 85

Flat wire

This propriety steel grade has high carbon content. It is especially intended for applications where high tensile strength is demanded.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)
0.80 - 0.95	0.10 - 0.30	0.30 - 0.60	0.025	0.020

Mechanical properties

For flat rolled wire

Width (mm)	Tolerance (mm)
4.00	±0.040
4.01 - 6.00	±0.070

Thickness (mm)	Tolerance (mm)	Tensile Strength (N/mm²)
1.00	±0.020	1965 -
1.01 - 1.50	±0.030	1900 -

Yield point

Yield strength: 80-90% of the tensile strength.

Elongation

Min%: 4

Camber

Max. 4 mm measured on 1 m length.

Surface conditions

Surface

Bright or oxide.
Surface defects max 1% of thickness.

Physical properties

Density: 7.95 kg/dm³.

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

JIS 1.1269

Nearest equivalent standards

EN 10270-1, AMS SA 905

Additional

Additional information

Edges
Natural edges (edge treatment on request).

Decarburization
No total decarburisation. Partial decarburisation (no continuous zones)
max 1.2% of a corresponding round wire dimension.

Diagram.: Thickness vs. Width

GARBAFLEX CrSi70

Flat and shaped wire

GARBAFLEX CrSi70 is especially intended for application requiring high fatigue properties and good relaxation properties at moderately increased working temperatures.

Chemical composition

C (%)	Si (%)	Mn (%)	Cr (%)	P max. (%)	S max. (%)
0.50 - 0.60	1.20 - 1.60	0.50 - 0.80	0.50 - 0.80	0.020	0.020

Mechanical properties

For flat rolled wire

Width (mm)	Tolerance (mm)
1.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.30 - 0.80	±0.013
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025
1.61 - 2.30	±0.050

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.01	±0.060

Microstructure

Tempered martensite with no ferrite.

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).
Profile drawn (shaped).

Camber

Max. 4 mm measured on 1 m length.

Coil set

Max. 20 mm measured on 1 m length.

Surface conditions

Surface

Bright or oxide.
Surface defects max. 1% of thickness.

Physical properties

Density: 7.95 kg/dm³.

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN/DIN 2090, AISI/SAE 2090, JIS 54SiCr6

Nearest equivalent standards

EN 10270-2, ASTM A401

Additional

Additional information

Decarburization
No total decarburisation. Partial decarburisation (no continuous zones) max. 1.2% of a corresponding round wire dimension.

GARBAFLEX CrSi75

Flat and shaped wire

GARBAFLEX CrSi75 is especially intended for application requiring high fatigue properties and good relaxation properties at moderately increased working temperatures.

Chemical composition

C (%)	Si (%)	Mn (%)	Cr (%)	V (%)	P max. (%)	S max. (%)
0.50 - 0.70	1.20 - 1.65	0.50 - 0.80	0.50 - 1.00	0.05 - 0.20	0.020	0.020

Mechanical properties

For flat rolled wire

Width (mm)	Tolerance (mm)
1.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.30 - 0.80	±0.013
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025
1.61 - 2.30	±0.050

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.01	±0.060

Microstructure

Tempered martensite with no ferrite.

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).
Profile drawn (shaped).

Camber

Max. 4 mm measured on 1 m length.

Coil set

Max. 20 mm measured on 1 m length.

Surface conditions

Surface

Bright or oxide.
Surface defects max. 1% of thickness.

Physical properties

Density: 7.95 kg/dm³.

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN/DIN 2090, AISI/SAE 2090, JIS 67SiCr5

Nearest equivalent standards

EN 10270-2

Additional

Additional information

Decarburization
No total decarburisation. Partial decarburisation (no continuous zones) max. 1.2% of a corresponding round wire dimension.

GARBAFLEX CrSi91

Flat and shaped wire for surface nitriding

GARBAFLEX CrSi91 is especially intended for application requiring extremely high fatigue properties and good relaxation properties at increased working temperatures.

Chemical composition

C (%)	Si (%)	Mn (%)	Cr (%)	V (%)	Mo (%)	P max. (%)	S max. (%)
0.50 - 0.70	1.80 - 2.20	0.30 - 0.60	0.80 - 1.00	0.05 - 0.15	0.05 - 0.15	0.020	0.020

Mechanical properties

For flat rolled wire

Width (mm)	Tolerance (mm)
1.00 - 5.00	±0.050
5.01 - 8.00	±0.070
8.01 - 10.00	±0.100

Thickness (mm)	Tolerance (mm)
0.30 - 0.80	±0.013
0.81 - 1.00	±0.019
1.01 - 1.60	±0.025
1.61 - 2.30	±0.050

For shaped wire

Width (mm)	Tolerance (mm)
1.50	±0.020
1.51 - 3.00	±0.030
3.01 - 5.00	±0.040
5.01 - 7.00	±0.050
7.01	±0.060

Microstructure

Tempered martensite with no ferrite.

Execution

Rolled on 2 sides (flat).
Rolled on 4 sides (shaped).
Profile drawn (shaped).

Camber

Max. 4 mm measured on 1 m length.

Coil set

Max. 20 mm measured on 1 m length.

Surface conditions

Surface

Bright or oxide.
Surface defects max. 1% of thickness.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN/DIN 2090, AISI/SAE 2090, JIS 67SiCr5

Recommendations

Soft shot peening

Before the nitriding process a soft shot peening process shall be applied in order to remove the oxide layer on the spring wire surface.

Nitriding

GARBAFLEX CrSi91 should be nitrided to obtain optimum fatigue and relaxation properties. Our recommendation is gas nitriding.

Additional

Additional information

Decarburisation
No total decarburisation. Partial decarburisation (no continuous zones) max. 1.2% of a corresponding round wire dimension.

KD

70 KD

Oil tempered SiCr-alloyed clutch and transmission spring wire

70 KD is especially intended for the manufacture of clutch and transmission springs and similar moderately high fatigue stressed springs. 70 KD S is a shaved version of 70 KD intended for applications with higher surface requirements. The material has good relaxation properties. The wire is manufactured in sizes from Ø 0.50 to 7.00 mm. Sizes from Ø 7.00 to 15.00 mm is manufactured in unshaved version. Other wire sizes and shapes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)
0.50 - 0.60	1.20 - 1.60	0.50 - 0.80	0.025	0.020	0.50 - 0.80

Cleanliness in steel

Non-metallic inclusions:
Max. level 2 according to DIN 50602-M.
Corresponding standard: ASTM E-45-A.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 60 N/mm².
4) Torsion test is carried out at ≤ 6.0 mm for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Torsions (l=300 mm, min. revs)	Reduct. of area (min. %)
0.50 - 0.80	±0.010	2080 - 2210	6
0.81 - 1.30	±0.015	2080 - 2210	5	50
1.31 - 1.40	±0.015	2080 - 2210	5	50
1.41 - 1.60	±0.020	2080 - 2210	5	50
1.61 - 2.00	±0.020	2010 - 2160	5	50
2.01 - 2.50	±0.020	1960 - 2060	5	50
2.51 - 3.00	±0.020	1910 - 2010	4	50
3.01 - 3.20	±0.020	1910 - 2010	4	45
3.21 - 3.50	±0.025	1910 - 2010	4	45
3.51 - 4.50	±0.025	1860 - 1960	4	45
4.51 - 5.00	±0.025	1810 - 1910	3	45
5.01 - 5.60	±0.030	1810 - 1910	3	40
5.61 - 6.00	±0.035	1760 - 1860	3	40
6.01 - 6.50	±0.035	1760 - 1860		40
6.51 - 7.00	±0.040	1710 - 1810		30
7.01 - 8.00	±0.045	1710 - 1810		30
8.01 - 9.00	±0.045	1660 - 1760		30
9.01 - 10.00	±0.050	1660 - 1760		30
10.01 - 12.00	±0.060	1610 - 1760		30
12.01 - 15.00	±0.060	1610 - 1760		30

Yield point

The proof stress R_p0.2 is min. 0.9 x tensile strength of the wire.

Surface conditions

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment ; for 70 KD a level of 60 microns and for 70 KD S of 40 microns. For 70 KDS diameter 6.60-8.60 mm, 60 microns. For size range 6.01-8.60 mm unshaved is tested continuously in Eddy Current equipment to a surface level of ≥ 80 microns. For diameter 6.60 - 8.60 unshaved 80 microns. For diameter 2.70-15.00 mm unshaved 100 microns.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure. Max. permissible depth of partial surface decarburization and surface defects, 1.3% x wire diameter. No complete decarburization allowed.

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment ; for 70 KD a level of 60 microns and for 70 KD S of 40 microns. For 70 KDS diameter 6.60-8.60 microns. For size range 6.01-8.60 mm unshaved is tested continuously in Eddy Current equipment to a surface level of ≥ 80 microns. For diameter 6.60 - 8.60 unshaved 80 microns. For diameter 2.70-15.00 mm unshaved 100 microns.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure. Max. permissible depth of partial surface decarburization and surface defects, 1.3% x wire diameter. No complete decarburization allowed.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN TDSiCr, SIS 142090-05

Nearest equivalent standards

ASTM A1000 A, BS 2803 685A55ND

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment. Shot peening of the inside of the spring coils is particularly critical.

75 KD

Oil tempered SiCrV-alloyed clutch and transmission spring wire

75 KD is especially intended for the manufacture of clutch and transmission springs and similar moderately high fatigue stressed springs.
75 KD S is a shaved version of 75 KD intended for applications with higher surface requirements.
The material has good relaxation properties. The wire is manufactured in sizes from Ø 1.60 to 7.00 mm. Other wire sizes and shapes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	V (%)
0.50 - 0.70	1.20 - 1.65	0.50 - 0.80	0.025	0.020	0.50 - 1.00	0.05 - 0.20

Cleanliness in steel

Non-metallic inclusions:
Max. level 2 according to DIN 50602-M.
Corresponding standard: ASTM E-45-A.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 60 N/mm².
4) Torsion test is carried out for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Torsions (l=300 mm, min. revs)	Reduct. of area (min. %)
1.60 - 2.00	±0.020	2160 - 2310	5	45
2.01 - 2.50	±0.020	2110 - 2210	5	45
2.51 - 3.20	±0.020	2060 - 2160	4	45
3.21 - 4.00	±0.025	2010 - 2110	4	45
4.01 - 5.00	±0.025	1960 - 2060	4	45
5.01 - 5.60	±0.030	1910 - 2010	4	40
5.61 - 6.00	±0.035	1910 - 2010	3	40
6.01 - 6.50	±0.035	1910 - 2010		40
6.51 - 7.00	±0.035	1860 - 2010		40

Yield point

The proof stress R_p0.2is min. 0.9 x tensile strength of the wire.

Surface conditions

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment; for 75 KD a level of 60 microns and for 75 KD S of 40 microns.
Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.
Max. permissible depth of partial surface decarburization and surface defects, 1.3% x wire diameter. No complete decarburization allowed.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN TDSiCrV

Nearest equivalent standards

ASTM A1000 D

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment. Shot peening of the inside of the spring coils is particularly critical.

75 KDH

Oil tempered SiCrV-alloyed spring wire

75 KDH is especially intended for the manufacture of springs exposed to high static loads or low cycle fatigue applications specially intended for trunk opening springs.

75 KDH is a SiCrV spring steel with elevated tensile strength.

The material has good relaxation properties. The wire is manufactured in sizes from Ø 2.50 to 5.00 mm. Other wire sizes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	V (%)
0.50 - 0.70	1.35 - 1.60	0.40 - 0.80	0.025	0.020	0.50 - 0.80	0.05 - 0.20

Cleanliness in steel

Non-metallic inclusions:
Max. level 2 according to DIN 50602-M.
Corresponding standard: ASTM E-45-A.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 60 N/mm².
4) Torsion test is carried out for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Torsions (l=300 mm, min. revs)	Reduct. of area (min. %)
2.50 - 3.20	±0.020	2240 - 2340	4	40
3.21 - 3.50	±0.025	2240 - 2340	3	40
3.51 - 4.00	±0.025	2220 - 2320	3	40
4.01 - 4.50	±0.025	2220 - 2320	3	38
4.51 - 5.00	±0.030	2200 - 2300	3	38

Yield point

The proof stress R_p0.2 is min. 0.87 x tensile strength of the wire.

Surface conditions

Surface condition

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.

Max. permissible depth of partial surface decarburization and surface defects, 1.3% x wire diameter. No complete decarburization allowed.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN TDSiCrV

Nearest equivalent standards

EN 10270-2

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or
stress relieved. In order to reach optimum fatigue and relax- ation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment. Shot peening of the inside of the spring coils is particularly critical.

OTEVA

OTEVA 101 SC

Oil tempered SiCrVMoW-alloyed ultra-high tensile clutch and transmission spring wire for surface nitriding.

OTEVA® 101 SC is a Super Clean steel, especially intended for the manufacture of clutch and transmission springs and other springs requiring high fatigue properties and good relaxation properties at increased working temperatures.

Manufactured as standard in shaved condition in sizes from Ø 2.00 mm to 5.00 mm or in egg or elliptical shape corresponding to round cross section 2.50 mm to 5.00 mm. Other wire sizes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	V (%)	Mo (%)	W (%)
0.50 - 0.70	2.10 - 2.40	0.30 - 0.70	0.020	0.030	1.10 - 1.40	0.05 - 0.25	0.05 - 0.25	0.05 - 0.25

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat in accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area 1 000 mm².

Inclusion size, surface	5–10	> 10–15	>15 µm
Max. number of inclusions	50	7	0

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Torsions (l=300 mm, min. revs)	Reduct. of area (min. %)
2.00 - 2.50	±0.020	2100 - 2200	2	40
2.51 - 3.20	±0.020	2100 - 2200	2	40
3.21 - 4.00	±0.025	2100 - 2200	2	40
4.01 - 5.00	±0.025	2100 - 2200	2	40

Surface conditions

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 5.00 mm the wire is tested continuously in Eddy Current equipment to a surface level of ≥ 40 microns. Other wire sizes on request.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure. Max. permissible depth of partial surface decarburization and surface defects, 0.5% x wire diameter. No complete decarburization allowed.

Standards

Nearest equivalent standards

EN 10270-2

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved. Depending on nitriding temperature used later in the spring manufacturing process, this temperature may be decreased.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Soft shot peening

Before the nitriding process a soft shot peening process shall be applied in order to remove the oxide layer on the spring wire surface.

Nitriding

Springs of OTEVA® 101 SC must be nitrided to obtain optimum fatigue and relaxation properties. Our recommendation is gas nitriding.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

For nitrided springs with an extremely hard surface zone, it is important to use a shot peening media with high hardness.

Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:
Wire diameter	Ø 3.85 mm
Diameter external	26.95
Spring length, I0	53.0
N active	4.15
Spring index	6.0
Stress relieving
Temperature	450°C (790 ±10 °F)
Time	30 minutes
Soft shot peened
Speed	20-30 m/s
Time	5 min
Shot size	0.8 mm
Nitriding	Gas nitriding
Temperature	450-470°C
Time	5-20 hours
Aim for surface hardness	Min. 850 Hv
Aim for core hardness	Min. 610 Hv
Compound (white) layer	Max. 1 µm.
Shot peening (triple shot peening for nitrided springs)
1st treatment	Pressure 0.3 MPa with RCW shoot size 0.6 mm (hardness 800 Hv) for 20 minutes.
2nd treatment	Pressure 0.3 MPa with RCW shoot size 0.25 mm (hardness 800 Hv) for 10 minutes.
3rd treatment	Pressure 0.2 MPa with fine shoot size (hardness 700 HV) for 10 minutes.
Aim for Almen arc-height	0.55 – 0.60 mm
Hot presetting	1500 N/mm2 (nitrided springs)
(theoretically set)	1300 N/mm2 (not nitrided springs)
Temperature	200°C (max. 250°C)
Time	10 minutes

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of nitrided springs made from OTEVA® 101 SC wire subjected to static compression at different temperatures, nitrided/not nitrided.

OTEVA 70 SC, OTEVA 70 SC PLUS

Suzuki Garphyttan www.suzuki-garphyttan.com

OTEVA 70 SC, OTEVA 70 SC PLUS

Oil tempered SiCr-alloyed valve spring wire

OTEVA® 70 SC is a Super Clean steel, especially intended for the manufacture of clutch/ transmission springs with extremely high fatigue properties and good relaxation properties at moderately increased working temperature. The wire is manufactured in shaved condition in sizes from Ø 0.50 mm to 10.0 mm, or in egg or elliptical shape corresponding to round cross section 2.50 mm to 6.50 mm Other wire sizes and shapes on request.

OTEVA® 70 SC PLUS is intended for manufacture of valve springs and other springs requiring extremely high fatigue properties and good relaxation properties at increased working temperatures. Further information about the approval process for OTEVA SC PLUS is found here.

Chemical composition

C (%) Si (%) Mn (%) P max. (%) S max. (%) Cr (%)

0.50 - 0.60 1.20 - 1.60 0.50 - 0.80 0.025 0.020 0.50 - 0.80

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat of OTEVA® 70 SCin accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 1 000 mm².

Inclusion size, surface 5-10 µm >10-15 µm >15 µm

Max. number of inclusions 50 7 0

For OTEVA 70 SC PLUS, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 50 N/Mm².
4) Torsion test is carried out at ≤ 6.0 mm for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm) Tolerance (mm) Tensile Strength (N/mm²) Torsions (l=300 mm, min. revs) Reduct. of area (min. %)

0.50 - 0.80 ±0.010 2080 - 2210 6

0.81 - 1.30 ±0.015 2080 - 2210 5 50

1.31 - 1.40 ±0.015 2080 - 2210 5 50

1.41 - 1.60 ±0.020 2080 - 2210 5 50

1.61 - 2.00 ±0.020 2010 - 2160 5 50

2.01 - 2.50 ±0.020 1960 - 2060 5 50

2.51 - 3.00 ±0.020 1910 - 2010 4 50

3.01 - 3.20 ±0.020 1910 - 2010 4 45

3.21 - 3.50 ±0.025 1910 - 2010 4 45

3.51 - 4.50 ±0.025 1860 - 1960 4 45

4.51 - 5.00 ±0.025 1810 - 1910 3 45

5.01 - 5.60 ±0.030 1810 - 1910 3 40

5.61 - 6.00 ±0.035 1760 - 1860 3 40

6.01 - 6.50 ±0.035 1760 - 1860 40

6.51 - 7.00 ±0.040 1710 - 1810 40

7.01 - 8.00 ±0.045 1710 - 1810 40

8.01 - 9.00 ±0.045 1660 - 1760 35

9.01 - 10.00 ±0.050 1660 - 1760 35

Yield point

The proof stress R_p0.2 is min. 0.9 x tensile strength of the wire.

Surface conditions

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment to a surface level of ≥ 40 microns. For size range 6.01-8.60 mm is tested continuously in Eddy Current equipment to a surface level of ≥ 60 microns. Other wire sizes on request.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.

Max. permissible depth of partial surface decarburization and surface defects, 1 % x wire diameter. In shaved condition; for diameters <=2 .00 mm 10 µm, for diameters > 2.00 mm 0.5% x d. For diameters > 6.60-10.00 mm 0.7% x d.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN VDSiCr, SIS 142090-05

Nearest equivalent standards

EN 10270-2, ASTM A877 A, BS 2803 685A55HD, JIS G3561 SWOSC-V

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:

Wire size Ø 4.00 mm

Diameter external 28.00 mm

Spring length, l0 59.5 mm

N active 4.80

Spring index
6.0

Stress relieving

Temperature 420 ±5°C (790 ±10 °F)

Time 30 minutes

Shot peening
Speed 48 m/sec. for 20 minutes, size of shots 0.8 mm

Hardness of Shot-peening grit (shot): 610-670 Hv

Aim for Almen arc-height Min. 0.40-0.45 mm

Hot presetting (theoretically set) 1200 N/mm2

Temperature 200°C (max. 250°C)

Time 10 minutes

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of springs made from OTEVA® 70 SC wire subjected to static compression at different temperatures.

Additional

Additional information

Delivery forms
See separate sheet.
OTEVA 75 SC, OTEVA 75 SC PLUS

Suzuki Garphyttan www.suzuki-garphyttan.com

OTEVA 75 SC, OTEVA 75 SC PLUS

Oil tempered SiCrV-alloyed high tensile valve spring wire

OTEVA® 75 SC is a Super Clean steel, especially intended for the manufacture of clutch/ transmission springs with extremely high fatigue properties and good relaxation properties at moderately increased working temperatures.

Manufactured as standard in shaved condition in sizes from Ø 1.60 mm to 10.0 mm, or in egg or elliptical shape corresponding to round cross section 2.50 mm to 6.50 mm. Other wire sizes and shapes on request.

OTEVA® 75 SC PLUS is intended for manufacture of valve springs and other springs requiring extremely high fatigue properties and good relaxation properties at increased working temperatures.

Further information about the approval process for OTEVA SC PLUS is found here.

Chemical composition

C (%) Si (%) Mn (%) P max. (%) S max. (%) Cr (%) V (%)

0.50 - 0.70 1.20 - 1.65 0.50 - 0.80 0.020 0.020 0.50 - 1.00 0.05 - 0.20

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat of OTEVA® 75 SC in accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 1 000 mm².

Inclusion size, surface 5-10 µm >10-15 µm >15 µm

Max. number of inclusions 50 7 0

For OTEVA 75 SC PLUS, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

For round wire

Diameter (mm) Tolerance (mm) Tensile Strength (N/mm²) Torsions (l=300 mm, min. revs) Reduct. of area (min. %)

1.60 - 2.00 ±0.020 2160 - 2260 5 45

2.01 - 2.50 ±0.020 2110 - 2210 5 45

2.51 - 3.20 ±0.020 2060 - 2160 5 45

3.21 - 4.00 ±0.025 2010 - 2110 4 45

4.01 - 5.00 ±0.025 1960 - 2060 3 45

5.01 - 5.60 ±0.030 1910 - 2010 3 40

5.61 - 6.00 ±0.035 1910 - 2010 3 40

6.01 - 6.50 ±0.035 1910 - 2010 35

6.51 - 7.00 ±0.040 1910 - 2010 35

7.01 - 8.00 ±0.045 1860 - 1960 35

8.01 - 9.00 ±0.045 1860 - 1960 35

9.01 - 10.00 ±0.050 1860 - 1960 35

Yield point

The proof stress R_p0.2 is min. 0.9 x tensile strength of the wire.

Surface conditions

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment to a surface level of ≥ 40 microns. For size range 6.01-8.60 mm is tested continuously in Eddy Current equipment to a surface level of ≥ 60 microns. Other wire sizes on request.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.
Max. permissible depth of partial surface decarburization and surface defects, 1 % x wire diameter. In shaved condi-tion; for diameters <=2 .00 mm 10 µm, for diameters > 2.00 mm 0.5% x d. For diameters > 6.60-10.00 mm 0.7% x d.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN VDSiCrV

Nearest equivalent standards

ASTM A877 B

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:

Wire size Ø 4.00 mm

Diameter external 28.00 mm

Spring length, l0 59.5 mm

N active 4.80

Spring index 6.0

Stress relieving

Temperature 420 ±5°C (790 ±10 °F)

Time 30 minutes

Shot peening (double shot peening)

1st treatment Speed 56 m/sec. for 20 minutes, size of shots 0.8 mm

2nd treatment Speed 30 m/sec. for 10 minutes, size of shots 0.8 mm

Hardness of Shot-peening grit (shot): 610-670 Hv

Aim for Almen arc-height Min 0.45 mm

Hot presetting
(theoretically set) 1300 N/mm²

Temperature 200°C (max. 250°C)

Time 10 minutes

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of springs made from OTEVA® 75 SC wire subjected to static compression at different temperatures.
OTEVA 90 SC, OTEVA 90 SC PLUS

Suzuki Garphyttan www.suzuki-garphyttan.com

OTEVA 90 SC, OTEVA 90 SC PLUS

Oil tempered SiCrVNi-alloyed ultra-high tensile valve spring wire for
surface nitriding

OTEVA® 90 SC is a Super Clean steel, especially intended for the manufacture of clutch/transmission springs with extremely high fatigue properties and good relaxation properties at increased working temperatures.

Manufactured as standard in shaved condition in sizes from Ø 2.00 mm to 6.00 mm, or in egg or elliptical shape corresponding to round cross section 2.50 mm to 6.00 mm. Other wire sizes on request.

OTEVA® 90 SC PLUS is intended for manufacture of valve springs and other springs requiring extremely high fatigue properties and good relaxation properties at increased working temperatures.

Further information about the approval process for OTEVA SC PLUS is found here.

Chemical composition

C (%) Si (%) Mn (%) P max. (%) S max. (%) Cr (%) V (%) Ni (%)

0.50 - 0.70 1.80 - 2.20 0.70 - 1.00 0.020 0.020 0.85 - 1.05 0.05 - 0.15 0.20 - 0.40

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat of OTEVA® 90 SC in accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 1 000 mm².

Inclusion size, surface 5-10 µm >10-15 µm >15 µm

Max. number of inclusions 50 7 0

For OTEVA 90 SC PLUS, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 50 N/mm².
4) Torsion test is carried out for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm) Tolerance (mm) Tensile Strength (N/mm²) Torsions (l=300 mm, min. revs) Reduct. of area (min. %) Tensile strength after heat treatment 480C 1h (N/mm²)

2.00 - 2.50 ±0.020 2180 - 2280 5 45 -

2.51 - 3.20 ±0.020 2130 - 2230 5 45 5 -

3.21 - 4.00 ±0.025 2080 - 2180 4 45 -

4.01 - 5.00 ±0.025 2030 - 2130 3 45 -

5.01 - 5.60 ±0.030 1980 - 2080 3 40 -

5.61 - 6.00 ±0.035 1980 - 2080 3 40 -

Yield point

The proof stress R_p0.2 is min. 0.8 x tensile strength of the wire. The proof stress will rise above 0.9 x tensile strength after stress relieving the springs.

Surface conditions

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment to a surface level of ≥ 40 microns. Other wire sizes on request.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.
Max. permissible depth of partial surface decarburization and surface defects, 1 % x wire diameter. In shaved condi-tion; for diameters <=2 .00 mm 10 µm, for diameters > 2.00 mm 0.5% x d.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent standards

ASTM A877 C

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved. Depending on nitriding temperature used later in the valve spring manufacturing process, this temperature may be decreased.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Soft shot peening

Before the nitriding process a soft shot peening process shall be applied in order to remove the oxide layer on the spring wire surface.

Nitriding

Springs of OTEVA® 90 SC should be nitrided to obtain optimum fatigue and relaxation properties. Our recommendation is gas nitriding.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

For nitrided springs with an extremely hard surface zone, it is important to use a shot peening media with high hardness.

Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:

Wire size Ø 3.85 mm

Diameter external 26.95 mm

Spring length, l0 53.0 mm

N active 4.15

Spring index 6.0

Stress relieving

Temperature 450 ±5 °C (840 ±10 °F) min. 420 °C (790 ±10 °F) for nitriding

Time 30 minutes

Soft shot peened

Speed 20-30 m/s

Time 5 min

Shot size 0.8 mm

Nitriding Gas nitriding

Temperature 450-470°C

Time 5-20 hours

Aim for surface hardness Min. 800 Hv

Aim for core hardness Min. 560 Hv

Compound (white) layer Max. 1 µm.

Shot peening (triple shot peening for nitrided springs)

1st treatment Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.6 mm (hardness 800 Hv) f or 20 minutes.

2nd treatment 3rd treatment

Aim for Almen arc-height Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.25 mm (hardness 800 Hv) f or 10 minutes. Pressure 0.2 MPa (~40m/s)* with fine shot size (hardness 700 Hv) for 10 minutes. 0.55 – 0.60 mm

Hot presetting
(theoretically set) 1500 N/mm² (nitrided springs) 1300 N/mm² (not nitrided springs)

Temperature 200°C (max. 250°C)

Time 10 minutes

* Pressure setting for an air blast system and the approximate corresponding shot speed for a centrifugal blast wheel (in brackets).

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of springs made from OTEVA® 90 SC wire subjected to static compression at different temperatures, nitrided/not nitrided.
OTEVA 91 SC

Suzuki Garphyttan www.suzuki-garphyttan.com

OTEVA 91 SC

Oil tempered SiCrVMo-alloyed ultra-high tensile valve spring wire for surface nitriding

OTEVA® 91 SC is a Super Clean steel, especially intended for the manufacture of clutch/transmission springs with extremely high fatigue properties and good relaxation properties at increased working temperatures.
Manufactured as standard in shaved condition in sizes from Ø 2.00 mm to 10.0 mm, or in egg or elliptical shape corresponding to round cross section 2.50 mm to 6.00 mm. Other wire sizes on request.

OTEVA® 91 SC PLUS is intended for manufacture of valve springs and other springs requiring extremely high fatigue properties and good relaxation properties at increased working temperatures.

Further information about the approval process for OTEVA SC PLUS is found here.

Chemical composition

C (%) Si (%) Mn (%) P max. (%) S max. (%) Cr (%) V (%) Mo (%)

0.50 - 0.70 1.80 - 2.20 0.30 - 0.60 0.020 0.025 0.80 - 1.00 0.05 - 0.15 0.05 - 0.15

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat of OTEVA® 91 SC in accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 1 000 mm².

Inclusion size, surface 5-10 µm >10-15 µm >15 µm

Max. number of inclusions 50 7 0

For OTEVA 91 SC PLUS, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 50 N/mm².
4) Torsion test is carried out at ≤ 6.0 mm for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm) Tolerance (mm) Tensile Strength (N/mm²) Torsions (l=300 mm, min. revs) Reduct. of area (min. %)

2.00 - 2.50 ±0.020 2180 - 2280 5 45

2.51 - 3.20 ±0.020 2130 - 2230 5 45

3.21 - 4.00 ±0.025 2080 - 2180 4 45

4.01 - 5.00 ±0.025 2030 - 2130 3 45

5.01 - 5.60 ±0.030 1980 - 2080 3 40

5.61 - 6.00 ±0.035 1980 - 2080 3 40

6.01 - 7.00 ±0.040 1910 - 2010 35

7.01 - 8.00 ±0.045 1860 - 1960 35

8.01 - 9.00 ±0.045 1860 - 1960 35

9.01 - 10.00 ±0.050 1860 - 1960 35

Yield point

The proof stress R_p0.2 is min. 0.8 x tensile strength of the wire. The proof stress will rise above 0.9 x tensile strength after stress relieving the springs.

Surface conditions

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment to a surface level of ≥ 40 microns. For size range 6.01-8.60 mm is tested continuously in Eddy Current equipment to a surface level of ≥ 60 microns. Other wire sizes on request.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.
Max. permissible depth of partial surface decarburiza-tion and surface defects, 1 % x wire diameter. In shaved condition; for diameters <=2 .00 mm 10 µm, for diameters > 2.00 mm 0.5% x d. For diameters > 6.60-10.00 mm 0.7% x d.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent standards

ASTM A877 D

Recommendations

Oil tempered SiCrVMo-alloyed ultra-high tensile valve spring wire for surface nitriding

Heat treatment

As soon as possible after coiling, the springs should be stress relieved. Depending on nitriding temperature used later in the valve spring manufacturing process, this temperature may be decreased.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Soft shot peening

Before the nitriding process a soft shot peening process shall be applied in order to remove the oxide layer on the spring wire surface.

Nitriding

Springs of OTEVA® 91 SC should be nitrided to obtain optimum fatigue and relaxation properties. Our recommendation is gas nitriding.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

For nitrided springs with an extremely hard surface zone, it is important to use a shot peening media with high hardness. Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:

Wire size Ø 3.85 mm

Diameter external 26.95 mm

Spring length, l0 53.0 mm

N active 4.15

Spring index 6.0

Stress relieving

Temperature 450 ±5 °C (840 ±10 °F) min. 420 °C (790 ±10 °F) for nitriding

Time 30 minutes

Soft shot peened

Speed 20-30 m/s

Time 5 min

Shot size 0.8 mm

Nitriding Gas nitriding

Temperature 450-470°C

Time 5-20 hours

Aim for surface hardness Min. 800 Hv

Aim for core hardness Min. 560 Hv

Compound (white) layer Max. 1 µm.

Shot peening (triple shot peening for nitrided springs)

1st treatment Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.6 mm (hardness 800 Hv) for 20 minutes.

2nd treatment 3rd treatment

Aim for Almen arc-height Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.25 mm (hardness 800 Hv) for 10 minutes. Pressure 0.2 MPa (~40m/s)* with fine shot size (hardness 700 Hv) for 10 minutes. 0.55 – 0.60 mm

Hot presetting
(theoretically set) 1500 N/mm² (nitrided springs) 1300 N/mm² (not nitrided springs)

Temperature 200°C (max. 250°C)

Time 10 minutes

* Pressure setting for an air blast system and the approximate corresponding shot speed for a centrifugal blast wheel (in brackets).

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of springs made from OTEVA® 91 SC wire subjected to static compression at different temperatures, nitrided/not nitrided.
OTEVA 96 SC, OTEVA 96 SC PLUS

Suzuki Garphyttan www.suzuki-garphyttan.com

OTEVA 96 SC, OTEVA 96 SC PLUS

Oil tempered SiCrVMo-alloyed ultra-high tensile valve spring wire for
surface nitriding

OTEVA® 96 SC is a Super Clean steel, especially intended for the manufacture of clutch/transmission springs with extremely high fatigue properties and good relaxation properties at increased working temperatures.

Manufactured as standard in shaved condition in sizes from Ø 2.00 mm to 6.00 mm, or in egg or elliptical shape corresponding to round cross section 2.50 mm to 6.00 mm. Other wire sizes on request.

OTEVA® 96 SC PLUS is intended for manufacture of valve springs and other springs requiring extremely high fatigue properties and good relaxation properties at increased working temperatures.

Further information about the approval process for OTEVA SC PLUS is found here.

Chemical composition

C (%) Si (%) Mn (%) P max. (%) S max. (%) Cr (%) V (%) Mo (%)

0.60 - 0.70 2.00 - 2.20 0.30 - 0.60 0.020 0.025 0.90 - 1.00 0.10 - 0.15 0.10 - 0.15

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat in accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area 1 000 mm².

Inclusion size, surface 5-10 µm >10-15 µm >15 µm

Max. number of inclusions 50 7 0

For OTEVA 96 SC PLUS, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 50 N/mm².
4) Torsion test is carried out for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm) Tolerance (mm) Tensile Strength (N/mm²) Torsions (l=300 mm, min. revs) Reduct. of area (min. %)

2.00 - 2.50 ±0.020 2180 - 2280 5 45

2.51 - 3.20 ±0.020 2130 - 2230 5 45

3.21 - 4.00 ±0.025 2080 - 2180 4 45

4.01 - 5.00 ±0.025 2030 - 2130 3 45

5.01 - 5.60 ±0.030 1980 - 2080 3 40

5.61 - 6.00 ±0.035 1980 - 2080 3 40

Yield point

The proof stress R_p0.2 is min. 0.8 x tensile strength of the wire. The proof stress will rise above 0.9 x tensile strength after stress relieving the springs.

Surface conditions

Surface condition

Surface condition - non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment to a surface level of ≥ 40 microns. Other wire sizes on request.

Surface condition - end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure. Max. permissible depth of partial surface decarburization and surface defects, 1 % x wire diameter. In shaved condition; for diameters <=2 .00 mm 10 µm, for diameters > 2.00 mm 0.5% x d.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent standards

EN 10270-2

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved. Depending on nitriding temperature used later in the valve spring manufacturing process, this tem-perature may be decreased.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Soft shot peening

Before the nitriding process a soft shot peening process shall be applied in order to remove the oxide layer on the spring wire surface.

Nitriding

Springs of OTEVA® 96 SC should be nitrided to obtain optimum fatigue and relaxation properties. Our recommendation is gas nitriding.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.
For nitrided springs with an extremely hard surface zone, it is important to use a shot peening media with high hardness.
Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:

Wire size Diameter external Spring length, l0 N active Ø 3.85 mm 26.95 mm 53.0 mm 4.15

Spring index 6.0

Stress relieving

Temperature 450 ±5 °C (840 ±10 °F) min. 420 °C (790 ±10 °F) for nitriding

Time 30 minutes

Soft shot peened

Speed 20-30 m/s

Time 5 min

Shot size 0.8 mm

Nitriding Gas nitriding

Temperature 450-470°C

Time 5-20 hours

Aim for surface hardness Min. 800 Hv

Aim for core hardness Min. 560 Hv

Compound (white) layer Max. 1 µm.

Shot peening (triple shot peening for nitrided springs)

1st treatment Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.6 mm (hardness 800 Hv) for 20 minutes.

2nd treatment 3rd treatment
Aim for Almen arc-height Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.25 mm (hardness 800 Hv) for 10 minutes. Pressure 0.2 MPa (~40m/s)* with fine shot size (hardness 700 Hv) for 10 minutes.. 0.55 – 0.60 mm

Hot presetting
(theoretically set) 1500 N/mm² (nitrided springs) 1300 N/mm² (not nitrided springs)

Temperature 200°C (max. 250°C)

Time 10 minutes

* Pressure setting for an air blast system and the approximate corresponding shot speed for a centrifugal blast wheel (in brackets).

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of springs made from OTEVA® 96 SC wire subjected to static compression at different temperatures, nitrided/not nitrided.

STATO

STATO 70

Oil tempered SiCr-alloyed spring wire (according to EN 10270-2 ; 2011 FD SiCr)

STATO 70 is especially intended for the manufacture of springs exposed to static or moderately high fatigue stresses. The material has good relaxation properties.

The wire is manufactured in sizes from Ø 0.50 mm to 7.00 mm. Other wire sizes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)
0.50 - 0.60	1.20 - 1.60	0.50 - 0.90	0.030	0.025	0.50 - 0.80

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 70 N/mm².
4) Min No of twists in the torsion test, Nt, are to be agreed upon.

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Reduct. of area (min. %)
0.50 - 0.60	±0.010	2100 - 2300
0.61 - 0.80	±0.010	2100 - 2300
0.81 - 1.00	±0.015	2100 - 2300
1.01 - 1.30	±0.020	2070 - 2260	45
1.31 - 1.40	±0.020	2060 - 2250	45
1.41 - 1.60	±0.020	2040 - 2220	45
1.61 - 2.00	±0.025	2000 - 2180	45
2.01 - 2.50	±0.025	1970 - 2140	45
2.51 - 2.70	±0.025	1950 - 2120	45
2.71 - 3.00	±0.030	1930 - 2100	45
3.01 - 3.20	±0.030	1910 - 2080	45
3.21 - 3.50	±0.030	1900 - 2060	42
3.51 - 4.00	±0.030	1870 - 2030	42
4.01 - 4.20	±0.035	1860 - 2020	40
4.21 - 4.50	±0.035	1850 - 2000	40
4.51 - 4.70	±0.035	1840 - 1990	40
4.71 - 5.00	±0.035	1830 - 1980	40
5.01 - 5.60	±0.035	1800 - 1950	38
5.61 - 6.00	±0.040	1780 - 1930	38
6.01 - 6.50	±0.040	1760 - 1910	35
6.51 - 7.00	±0.040	1740 - 1890	35

Surface conditions

Surface condition

Surface condition – end sample test

The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.

Max. permissible depth of partial surface decarburization and surface defects, 1.5% x wire diameter. No complete decarburization allowed.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN FDSiCr, SIS 142090-05

Nearest equivalent standards

ASTM A401, BS 2803 685A55HS, JIS G3561 SWOSC-V

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment. Shot peening of the inside of the spring coils is particularly critical.

STATO 75

Oil tempered SiCrV-alloyed spring wire (according to EN 10270-2; 2011 FD SiCrV)

STATO 75 is especially intended for the manufacture of springs exposed to static or moderately high fatigue stresses. The material has good relaxation properties.

The wire is manufactured in sizes from Ø 2.00 mm to 7.00 mm. Other wire sizes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	V (%)
0.50 - 0.70	1.20 - 1.65	0.40 - 0.90	0.030	0.025	0.50 - 1.00	0.10 - 0.15

Mechanical properties

1) Min No of twists in the torsion test, Nt, are to be agreed upon.

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Reduct. of area (min. %)
2.01 - 2.50	±0.025	2160 - 2310	45
2.51 - 2.70	±0.025	2110 - 2260	45
2.71 - 3.20	±0.030	2110 - 2260	45
3.21 - 3.50	±0.030	2110 - 2260	42
3.51 - 4.00	±0.030	2060 - 2210	42
4.01 - 5.00	±0.035	2060 - 2210	40
5.01 - 5.60	±0.035	2010 - 2160	38
5.61 - 6.00	±0.040	1960 - 2110	38
6.00 - 6.50	±0.040	1960 - 2110	35
6.51 - 7.00	±0.040	1960 - 2110	35

Surface conditions

Surface condition

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.

Max. permissible depth of partial surface decarburization and surface defects, 1.5% x wire diameter. No complete decarburization allowed.

Physical properties

E and G modulus of elasticity

About 206 kN/mm²

E and G modulus of shear

About 79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN FDSiCrV

Nearest equivalent standards

EN 10270-2

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment. Shot peening of the inside of the spring coils is particularly critical.

SWOSC

SWOSC-V

Oil tempered SiCr-alloyed valve spring wire
Only manufactured in China

SWOSC-V is a Super Clean steel, especially intended for the manufacture of valve springs and other springs requiring high fatigue properties and good relaxation properties at moderately increased working temperature.

The wire is manufactured in shaved condition in sizes from Ø 1.60 mm to 6.50 mm, or in egg or elliptical shape (corresponding to round cross section 2.50 mm to 6.50 mm). Other wire sizes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)
0.50 - 0.60	1.20 - 1.60	0.50 - 0.80	0.025	0.020	0.50 - 0.80

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat of SWOSC-V in accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 1 000 mm².

Inclusion size, surface	5-10 µm	>10-15 µm	>15 µm
Max. number of inclusions	50	7	0

For SWOSC-V, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

1) Other wire sizes on request.
2) Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3) Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 50 N/Mm².
4) Torsion test is carried out for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Torsions (l=300 mm, min. revs)	Reduct. of area (min. %)
1.60 - 2.00	±0.020	2010 - 2160	5	50
2.01 - 2.50	±0.020	1960 - 2060	5	50
2.51 - 3.00	±0.020	1910 - 2010	4	50
3.01 - 3.20	±0.020	1910 - 2010	4	45
3.21 - 3.50	±0.025	1910 - 2010	4	45
3.51 - 4.50	±0.025	1860 - 1960	4	45
4.51 - 5.00	±0.025	1810 - 1910	3	45
5.01 - 5.60	±0.030	1810 - 1910	3	40
5.61 - 6.00	±0.035	1760 - 1860	3	40
6.01 - 6.50	±0.035	1760 - 1860		40

Yield point

The proof stress R_p0.2 is min. 0.9 x tensile strength of the wire.

Surface conditions

Surface condition

Surface condition – non-destructive testing
In the standard size range 2.00 - 6.00 mm the wire is tested continuously in Eddy Current equipment to a surface level of ≥ 40 microns. Other wire sizes on request.

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.

Max. permissible depth of partial surface decarburization and surface defects, 1 % x wire diameter. In shaved condition; for diameters <=2 .00 mm 10 µm, for diameters > 2.00 mm 0.5% x d.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN VDSiCr, SIS 142090-05

Nearest equivalent standards

EN 10270-2, ASTM A877, BS 2803 685A55HD, JIS G3561 SWOSC-V

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:
Wire size	Ø 4.00 mm
Diameter external	28.00 mm
Spring length, l0	59.5 mm
N active	4.80
Spring index	6.0
Shot peening	Speed 48 m/sec. for 20 minutes, size of shots 0.8 mm
Hardness of Shot-peening grit (shot):	610-670 Hv
Aim for Almen arc-height	Min. 0.40-0.45 mm
Hot presetting (theoretically set)	1200 N/mm²
Temperature	200°C (max. 250°C)
Time	10 minutes

The presence of non-metallic inclusions in the wire rod is inspected for every heat of SWOSC-V in accordance with the Suzuki Garphyttan method by the steel supplier. Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following; For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 1 000 mm².

Inclusion size, surface	5-10 µm	>10-15 µm	>15 µm
Max. number of inclusions	50	7	0

For SWOSC-V, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of springs made from SWOSC-V wire subjected to static compression at different temperatures.

Additional

Additional information

Delivery forms

See separate sheet.

SWOSC-VHV

Oil tempered SiCrV-alloyed high tensile valve spring wire
Only manudactured in China

SWOSC-VHV is a Super Clean steel, especially intended for the manufacture of valve springs and other springs requiring high fatigue properties and good relaxation properties at moderately increased working temperatures.

The wire is manufactured in shaved condition in sizes from Ø 1.60 mm to 6.50 mm, or in egg or elliptical shape (corresponding to round cross section 2.50 mm to 6.50 mm). Other wire sizes on request.

Chemical composition

C (%)	Si (%)	Mn (%)	P max. (%)	S max. (%)	Cr (%)	V (%)
0.50 - 0.70	1.20 - 1.65	0.50 - 0.80	0.020	0.020	0.50 - 1.00	0.05 - 0.20

Cleanliness in steel

The presence of non-metallic inclusions in the wire rod is inspected for every heat of SWOSC-VHV in accordance with the Suzuki Garphyttan method by the steel supplier.

Before release for production, Suzuki Garphyttan performs non-metallic inclusion inspection for every fifth heat. The criteria for supplier inspection and releasing inspection are the following;

For wire rod samples: Inclusion size max. 15 µm down to 1 mm below surface. Inspection area: 1 000 mm².

Inclusion size, surface	5-10 µm	>10-15 µm	>15 µm
Max. number of inclusions	50	7	0

For SWOSC-VHV, every heat is inspected including a SEM-EDS analysis of inclusions > 10µm to verify a Super Clean composition.

As stated by IVSWMA, International Valve Spring Wire Manufacturers Association, it is likely to find occasional inclusions in valve spring quality steel of a size larger than 30 µm.

Mechanical properties

1)   Other wire sizes on request.
2)   Ovality, i. e. the difference between the largest and smallest dimension of a cross section, is maximum half the tolerance range.
3)   Conversion from tensile strength to hardness values can be calculated in standard ISO EN 18265. The tensile strength Rm within one coil does not vary more than 50 N/mm².
4) Torsion test is carried out for assessing deformability. The fracture of the torsion test piece shall be smooth and perpendicular to the wire axis. The rupture shall show no longitudinal cracks.

For round wire

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Torsions (l=300 mm, min. revs)	Reduct. of area (min. %)
1.60 - 2.00	±0.020	2160 - 2260	5	45
2.01 - 2.50	±0.020	2110 - 2210	5	45
2.51 - 3.20	±0.020	2060 - 2160	5	45
3.21 - 4.00	±0.025	2010 - 2110	4	45
4.01 - 5.00	±0.025	1960 - 2060	3	45
5.01 - 5.60	±0.030	1910 - 2010	3	40
5.61 - 6.00	±0.035	1910 - 20100	3	40
6.01 - 6.50	±0.035	1910 - 2010		35

Yield point

The proof stress Rp0.2 is min. 0.9 x tensile strength of the wire.

Surface conditions

Surface condition

Surface condition – end sample test
The wire is end sample tested by means of etch testing and binocular inspection as well as microscopical inspection of the material structure.
Max. permissible depth of partial surface decarburization and surface defects, 1 % x wire diameter. In shaved condition; for diameters <=2 .00 mm 10 µm, for diameters > 2.00 mm 0.5% x d.

Physical properties

E and G modulus of elasticity

206 kN/mm²

E and G modulus of shear

79.5 kN/mm²

Standards

Nearest equivalent steel grades

EN VDSiCrV

Nearest equivalent standards

EN 10270-2

Recommendations

Heat treatment

As soon as possible after coiling, the springs should be stress relieved.

Hot presetting

After shot peening, the springs should be hot preset or stress relieved. In order to reach optimum fatigue and relaxation properties, the springs must be preset at an appropriate stress.

Shot peening

In order to obtain optimum fatigue properties, the process time should be adjusted to get a complete treatment. Size of shots should be adapted to wire dimension, pitch and shot peening equipment.

Shot peening of the inside of the spring coils is particularly critical.

Spring Conditions For Tests

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:
Wire size	Ø 4.00 mm
Diameter external	28.00 mm
Spring length, l0	59.5 mm
N active	4.80
Spring index	6.0
Stress relieving
Temperature	420 ±5°C (790 ±10 °F)
Time	30 minutes
Shot peening (double shot peening)
1st treatment	Speed 56 m/sec. for 20 minutes, size of shots 0.8 mm
2nd treatment	Speed 30 m/sec. for 10 minutes, size of shots 0.8 mm
Hardness of Shot-peening grit (shot):	610-670 Hv
Aim for Almen arc-height	Min 0.45 mm
Hot presetting (theoretically set)	1300 N/mm²
Temperature	200°C (max. 250°C)
Time	10 minutes

Relaxation And Fatigue Properties

In diagram 1 the fatigue properties of this grade are illustrated in a Goodman-diagram, based on a special test spring design.

Diagram 2 shows the relaxation properties (loss of load) of springs made from SWOSC-VHV wire subjected to static compression at different temperatures.

Diameter (mm)	Tolerance (mm)	Tensile Strength (N/mm²)	Torsions (l=300 mm, min. revs)	Reduct. of area (min. %)	Tensile strength after heat treatment 480C 1h (N/mm²)
2.00 - 2.50	±0.020	2180 - 2280	5	45	-
2.51 - 3.20	±0.020	2130 - 2230	5	45	5 -
3.21 - 4.00	±0.025	2080 - 2180	4	45	-
4.01 - 5.00	±0.025	2030 - 2130	3	45	-
5.01 - 5.60	±0.030	1980 - 2080	3	40	-
5.61 - 6.00	±0.035	1980 - 2080	3	40	-

Spring conditions for fatigue and relaxation tests (specially designed test spring) Diagram 1 and 2:
Wire size Diameter external Spring length, l0 N active	Ø 3.85 mm 26.95 mm 53.0 mm 4.15
Spring index	6.0
Stress relieving
Temperature	450 ±5 °C (840 ±10 °F) min. 420 °C (790 ±10 °F) for nitriding
Time	30 minutes
Soft shot peened
Speed	20-30 m/s
Time	5 min
Shot size	0.8 mm
Nitriding	Gas nitriding
Temperature	450-470°C
Time	5-20 hours
Aim for surface hardness	Min. 800 Hv
Aim for core hardness	Min. 560 Hv
Compound (white) layer	Max. 1 µm.
Shot peening (triple shot peening for nitrided springs)
1st treatment	Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.6 mm (hardness 800 Hv) for 20 minutes.
2nd treatment 3rd treatment Aim for Almen arc-height	Pressure 0.3 MPa (~60m/s)* with RCW shot size 0.25 mm (hardness 800 Hv) for 10 minutes. Pressure 0.2 MPa (~40m/s)* with fine shot size (hardness 700 Hv) for 10 minutes.. 0.55 – 0.60 mm
Hot presetting (theoretically set)	1500 N/mm² (nitrided springs) 1300 N/mm² (not nitrided springs)
Temperature	200°C (max. 250°C)
Time	10 minutes