... G1000 2.high precision 3.Hardness:HRC58-62 1/4 ,G20 chrome bearing steel ballschrome bearing steel ball1 ... )material:AISI52100 GCr152)Size:1/8",1/4",3/16",5/16",5/32",3/ ... wearing, excellent surface quality and high hardness.7)Using:1. General industry for automobile, motorcycle, bicycle manufacturing, special ... we can according to customer need . 1/4 G20 chrome bearing steel balls