from 10mm-150mm, Cr from 1%-28%. Our products are high hardness:surface hardness of casting iron balls is to HRC 58-65. The toleranc of the core hardness and surface hardness is not over 2 HRC; good impact toughness: impact toughness of chrome balls is more than 4J/cm2;low broken rate:the actural broken rate is higher than 1%, good...