low carbon steel ball 1.size : 0.5mm to 60mm 2.Grade : G100, G200, G500.G1000,G2000 ... . Reference the accompanying chart for minimum case depth.Size Available: 0.5~ 60mmGrade Available:G100, G200, G500, G1000, G2000Application: Moderate loads ... , etc.CertificationISO 9002: 2000OriginalShandong province , China AISI 1020 LOW CARBON STEEL BALL (0.5MM-100MM)