Grinding Ball Hardened Steel 5.5-6 Mohs

Details:

Hardened steel grinding ball 1/4 in^ hardened steel grinding ball, for 3117 hardened tool steel vial set (2.5 Ml/5 ml), made of type 52-100 steel, composition: major element  fe; minor elements  cr, si, mn, c, durable and tough, diameter: 1/4in, hardne