... in Different Sizes and Grade Model Number:Steel Balls Stainless steel balls: size from 3/8 to 20 inches (DN10 ... 301, 304, 304L, 361 or 316L, ISO9001 approvals Chrome steel balls: material in GCr15 (E52100/100Cr6) Grades: G10, G25, G60, ... .5 to 50.8mm Hardness: HRC60 to 66 Carbon steel balls: material: AISI1010&1015 Grades: G100, G200, G500 or ... 1/8 to 1 inches Hardness: HRC60 to 66.5 Sell Steel Balls