... Head typesHexagon head,Mushroom head,Pan head,Countersunk head,Bugle head,Oval head,Hex flange head,Round head,Ball head,Button head...Socket typesPhillip type,Pozi type,Eleven type,hexagonal type,Torx ... ,is higher hardness than other.2.Fasteners' Head is much thicker ,it is strong not break ... control.6. Certificate:ISO9001-2008 ,And Provide dimensions report,chemical report and other testing report . ...