... :4.8 ,6.8,8.8,9.8.... Copper Bolts,Copper Bolt,Brass Bolts.1.What’s the specification of ... iron,such as 1022,1018,1010,1008,1015...Medium carbon steel are 35k,45#,10B21,1035,CH38F,1039,40ACR ... 100 equipment to produce fastener.Perfect quality 1.In Carbon Steel,The material are always use C1022 ,The percent ... is 0.18%-0.23% ,is higher than other Carbon Steel .2.Fasteners' Head is much thicker than some ...