Double End Bolt,Special 1.ISO,ANSI,CE,JIS,DIN,BS& ... 3.Grade:4.8 ,6.8,8.8,9.8... Double End Bolt,Special Head Bolt,Bolt Maker ,M6 Bolt Dimensions1 ... head,Hex flange head,Round head,Ball head,Button head...Socket typesPhillip type,Pozi type,Eleven type,hexagonal type,Torx type ... ,bit and spanner.When head become thicker,and then the socket is much deeper than some other manufacturers,it is convenient ...