size : 1/8" , 5/32", 3/16", 7/32", 1/4", 4mm, 5mm, 6mm MaterialAISI 1010-1015, AISI 1055, AISI1085Size1/8" , 5/32", 3/16", 7/32", 1/4", 4mm, 5mm, 6mmGradeG200, G500, G1000HardnessHRC60ApplicationCycle industryPackingBulk packing,pounch packing,plastic/tin box packing Factory Production Packing Style 1/4" Bicycle Steel Ball