low carbon steel ball 1.size : 0.5mm to 60mm 2.Grade : G100, G200, G500.G1000,G2000 3. ... High hardness with a soft core giving resistance to shock load & excellent resistance to surface wear.Hardness: Hardness is HRC 60 ... allow rotating parts, for example: castors, conveyors, roller skates, drawer slides, seat slides, bicycles, etc.CertificationISO 9002: 2000OriginalShandong province , China AISI 1020 ...