... 1)>40-50HRC: With this hardness, bearing steel grit will loses its sharp edges during shot basting process, it is particularly used for ... ≥60HRC:High hardness, sharp edges remain during operation, mainly used for marble cutting,characters: stable and reliable performance,even size , ... and operator and workers’ health. angular bearing steel grit used for rust cleaning and polishing etc, skype:qt.1131 QQ ...