... : G100--G1000 3) Hardness: HRC 55--65 4) Complying with GB, ASTM, DIN, JIS standards 5)good surface Features:Size ... : G100, G200, G500, G1000 Materials: Carbon steel, Chrome steel, Stainless steel, Copper, Aluminum Complying with GB, ASTM, DIN, JIS standards Use ... our company production of a kind of high quality carbon steel ball, with special heat treatment process, is extremely superior performance, ...