Product Description:Steel ShotSize: S780, S660, S550, S460, S390, S330, S280, S230, S170, S110, S70Chemistry Composition:C: 0.70-1.20%? Mn: 0.60-1.20%? Si: 0.40-1.20%? S: ?0.05%? P: ?0.05%Average degree of hardness:Normal: 40-50 HRC (377-509HV)Special: 52-56 HRC (543-620HV)Special: 56-60 HRC (620-713HV)Minimum density: 7.2g/cm3Package: 25kgs/bag, 40bags/ton/pallet Product Standard:1) American automobile engineer?s association ?SAE J827Cast steel shot standard?2) China black metallurgy profession?YB/T5149-93 cast steel shot? Product use:? Manufactured hypereutectoid steel abrasive ? Grey, metal spheres ? Used in airless wheel blast machines to clean foundry castings, surface polishing and shot peening ? Also used in portable trackblast airless wheel blast machines for concrete floor preparation and profiling ? Very long lasting ? Can be recycled many times ? Hardness: 40-50 HRc