Grade

Dia(mm)

Chemical Composition (%)

C

Si

Mn

P

S

Ni

Cr

Cu

Ti

Mo

45

18-60

0.42-0.50

0.17-0.37

0.50-0.80

≤0.035

≤0.035

≤0.30

≤0.25

≤0.25

55

0.52-0.60

0.17-0.37

0.50-0.80

≤0.035

≤0.035

≤0.30

≤0.25

≤0.25

40Mn2

0.37-0.44

0.17-0.37

1.40-1.80

≤0.035

≤0.035

≤0.30

20CrMnTi

0.17-0.23

0.17-0.37

0.80-1.10

≤0.035

≤0.035

1.00-1.30

0.04-0.10

20CrMo

0.17-0.24

0.17-0.37

0.40-0.70

≤0.035

≤0.035

0.80-1.10

0.15-0.25

30CrMo

0.26-0.34

0.17-0.37

0.40-0.70

≤0.035

≤0.035

0.80-1.10

0.15-0.25

35CrMo

0.32-0.40

0.17-0.37

0.40-0.70

≤0.035

≤0.035

0.80-1.10

0.15-0.25

42CrMo

0.38-0.45

0.17-0.37

0.50-0.80

≤0.035

≤0.035

0.90-1.20

0.15-0.25

60Si2MnA

0.38-0.45

0.17-0.37

0.50-0.80

≤0.035

≤0.035

0.90-1.20

0.15-0.25

Grade

Mechanical property
(Quenching, tempering, longitudinal)

Tensile strength
(σb/MPa)

Yield strength
(σs/MPa)

Elongation
(δ5/%)

Elongation
(δ10/%)

Percentage reduction of area
(ψ/%)

Impact absorbing energy
(AkU2/J)

45

≥600

≥335

≥16

≥40

39

55

≥645

≥380

≥13

≥35

-

40Mn2

≥885

≥735

≥12

≥45

55

20CrMnTi

≥1080

≥850

≥10

≥45

55

20CrMo

≥885

≥685

≥12

≥50

78

30CrMo

≥930

≥785

≥12

≥50

63

35CrMo

≥980

≥835

≥12

≥45

63

42CrMo

≥1080

≥930

≥12

≥45

63

60Si2MnA

≥1274

≥1176

≥5

≥25

-