... :HRC58-61 3.High precision,ABEC-1,P0 3/16 inch ,4.763mm ball bearing steel balls,used for bearings ABEC-1 ... bearing steel ball1)material:AISI52100 GCr152)Size:1/8",1/4",3/16",5/16",5/32",3/8"3)Grade ... 3. High - speed, low noise special bearing 4. Ball valves for liquid and gas etc.8)packing:inner packing:plastic bag/box ...