C

Si

Mn

Cr

S

P

0.50-0.65

0.15-0.37

0.6-1.2

≤0.25

≤0.04

≤0.04

0.7-0.9

0.45-0.75

0.7-1.25

0.40-0.60

≤0.04

≤0.04

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