Diameter mm

Tensile Strength N/mm2

Diameter mm

Tensile Strength N/mm2

Class A

Class B

Class A

Class B

0.6

-

2140 ~ 2400

1.7

1570 ~ 1800

1810 ~ 2030

0.63

-

2130 ~ 2380

1.8

1550 ~ 1780

1790 ~ 2010

0.65

-

2120 ~ 2370

1.9

1540 ~ 1760

1770 ~ 1990

0.7

-

2090 ~ 2350

2

1520 ~ 1750

1760 ~ 1970

0.75

-

2070 ~ 2320

2.1

1510 ~ 1730

1740 ~ 1960

0.8

-

2050 ~ 2300

2.25

1490 ~ 1710

1720 ~ 1930

0.85

-

2030 ~ 2280

2.4

1470 ~ 1690

1700 ~ 1910

0.9

-

2010 ~ 2260

2.5

1460 ~ 1680

1690 ~ 1890

0.95

-

2000 ~ 2240

2.6

1450 ~ 1660

1670 ~ 1880

1

1720 ~ 1970

1980 ~ 2220

2.8

1420 ~ 1640

1650 ~ 1850

1.05

1710 ~ 1950

1960 ~ 2200

3

1410 ~ 1620

1630 ~ 1830

1.1

1690 ~ 1940

1950 ~ 2190

3.2

1390 ~ 1600

1610 ~ 1810

1.2

1670 ~ 1910

1920 ~ 2160

3.4

1370 ~ 1580

1590 ~ 1780

1.25

1660 ~ 1900

1910 ~ 2140

3.6

1350 ~ 1560

1570 ~ 1760

1.3

1640 ~ 1890

1900 ~ 2130

3.8

1340 ~ 1540

1550 ~ 1740

1.4

1620 ~ 1860

1870 ~ 2100

4

1320 ~ 1520

1530 ~ 1730

1.5

1600 ~ 1840

1850 ~ 2080

4.25

1310 ~ 1500

1510 ~ 1700

2

1520 ~ 1750

1760 ~ 1970

Element

Composition, %

Carbon

0.45 – 0.85

Manganese

0.30 – 1.00

Phosphorus, max

0.040

Sulfur, max

0.050

Silicon

0.020

Class A

Tension, compression, torsion or shaped spring subjected to low static stress or rarely to dynamic stress.

Class B

Tension, compression, torsion or shaped spring subjected to medium and low static stress dynamic stress.