Balls subdivided into groupsby hardness:
1 - normal hardness of common purpose;
2 - hardened general purpose;
3 - high hardness for grinding ferrous metal ores;
4 - very high hardness for grinding nonferrous metal ores, cement, refractories.
| Section name | Production standard | HRC Hardness (HB), not less, for groups |
| | 1 | 2 | 3 | 4* | |
| | GOST 7524-89, DSTU 3499 | on the surface of the ball | | at a depth of ½ radius of the ball |
| 40 | 43 (401) | 49 (461) | 55 (534) | 55 (534) | 45 (415) |
| 60 | | | | | |
| 70 |
| 80 | 40 (352) | 42 (375) | 52 (495) | 52 (514) |
| 90 | | | | – | – |
| 100 | 52 (514) | 45 (415) |
| 120 | 35 (302) | 38 (331) | 50 (477) | – | – |
*Balls with a diameter of 80 mm, 100 mm very high hardness made of steel SH2L by TT 14788411-93-2009.
