... screw,drywall screw;Type "M","UNC","UNF","BSW"threads for Machine threads.Head typesHexagon head,Mushroom head,Pan head,Countersunk head,Bugle head,Oval head,Hex flange head,Round head,Ball head,Button head...Socket ... s hands.5. Recently,several New quality control equipments had brought to Enhance ... testing report . Almost each year ISO Quality person come into factory for Supervising inspecting. ...