... size : 5mm Grade : G200, G500, G1000 Certification: ISO 9002: 2000 Bicycle Steel Ball ItemBicycle steel ballMaterialAISI 1010-1015, AISI 1055, AISI1085Size1/8 ... 3.Products range :(a. )Material : carbon steel ball,stainless steel ball,chrome steel ball, gringding steel ball and so on.(b.)size : from 0 ... .5mm to 100mm(c.) grade : from G100 to G10004. an ISO 9002:2000 ...