Name

Material

C

Mn

Si

Cr

S

P

JC-1

50Mn

0.48-0.56

0.70-1.0

0.17-0.37

≤0.25

≤0.035

≤0.035

JC-2

60Mn

0.57-0.65

0.70-1.0

0.17-0.37

≤0.25

≤0.035

≤0.035

JC-3

65Mn

0.60-0.70

0.90-1.2

0.17-0.37

≤0.25

≤0.035

≤0.035

JC-4

B2

0.70-0.85

0.70-0.80

0.17-0.37

0.2-0.7

≤0.03

≤0.03

JC-5

75SiMn

0.70-0.90

0.70-1.20

0.4-0.8

≤0.25

≤0.03

≤0.03

JC-6

Wear-resistant Alloy

0.50-0.65

0.4-1.0

1.4-1.8

0.9-1.2

≤0.03

≤0.03

Nominal diameter

Diameteical

Tolerance

Weight of single ball in 

average

Surface

hardness

Impact

toughness

(mm)

(mm)

(g)

(HRC)

(j/cm)

Φ20

+2 -1

32

50-65

≥12

Φ25

+2   -1

64

50-65

≥12

Φ30

+2   -1

110

50-65

≥12

Φ40

+2   -1

263

50-65

≥12

Φ50

+2   -1

513

50-65

≥12

Φ60

+3   -2

888

50-65

≥12

Φ70

1410

Φ80

2104

Φ90

2996

Φ100

4110

Φ110

+4 -2

5457

50-65

Φ120

7102

Φ130

9030

Φ140

+4   -3

11278

50-65

  Φ150

13871