... :G100 to G1000 2.high precision 3.DRY,SOFT,NO HARDNESS 15mm chrome steel ballschrome bearing steel ball1)material:AISI52100 GCr152 ... ",5/16",5/32",3/8"3)Grade:G10-G10004)Hardness: HRC60-625) Producing standard:GB308-20026)Feature: Good wearing, ... excellent surface quality and high hardness.7)Using:1. General industry for automobile, motorcycle, bicycle manufacturing ...