1: diameter: 20~150mm 2: hrc: 50~65 3: material: steel 4:iso9001:2008 Detailed product description 1:unbreakable forged grinding steel ball 2: diameter: 20~150mm 3: hrc: 50~65 4: material: steel iso9001:2008 5: product performance A) even hardness, b) unbreakable C) grinding resistant, d) high impact value E) high combined efficiency of grinding mill 6: application fields A) industries of cement building material B) metallurgical selection in mine C) grinding coal in power plate D) chemical machinery