Items

Suface hardness(HRC)

Endurance impact test

Quenched

Unquenched

(Times)

High chrome Casting grinding balls

≥60

≥50

≥8000

Middle chrome Casting grinding balls

≥60

≥50

≥8000

Low chrome Casting grinding balls

≥60

≥45

≥8000

Item

SIZES

φ17

φ20

φ25

φ30

φ40

φ50

φ60

φ70

φ80

φ90

φ100

φ110

φ120

φ130

Tolerance

+1.0

+2.0

+3.0

+3.5

-1.0

-1.0

-1.0

-1.5

Difference between

max diam and min diam

≤1.0

≤2.0

≤3.0

Items

Brand

Chemical elements

C

Si

Mn

Cr

Mo

Cu

Ni

P

S

High chrome casting iron ball

JCCr20

2.0-3.0

≤1.0

0.5-1.5

18-22

0-2.5

0-1.2

0-1.5

≤0.10

≤0.10

High chrome casting grinding ball

JCCr15

2.0-3.0

≤1.0

0.5-1.5

14-17

0-3.0

0-1.0

0-1.5

≤0.10

≤0.10

High chrome casting grinding ball

JCCr13

2.0-3.0

≤1.0

0.5-1.5

11~14

0-1.0

0-2.0

0-1.5

≤0.10

≤0.10

Middle chrome casting grinding ball

JCCr7

2.1-3.2

0.5-2.2

0.5-1.5

6~10

0-1.0

0-0.8

0-1.5

≤0.10

≤0.10

Low chrome casting grinding ball

JCCr2

2.2-3.6

≤1.2

0.5-1.5

1.0-3.0

0-1.0

0-0.8

≤0.10

≤0.