This standard applies to steel grinding balls produced by rolling, forging, stamping and used for raw materials and materials grinding in ball mills. 2. NORMATIVE REFERENCES ... GOST 9012-59 (ISO 410-82, ISO 6506-81) Metals. Hardness measuring by Brinell method GOST 9013-59 (ISO 6508-86) Metals. ... Products with ball form for material crushing ...