... etc.2.Head type: Hexagon head, Mushroom head, Pan head, Countersunk head,Bugle head, Oval head, Hex flange head, Button head,Triangular head , Round head, Ball head ,Spherical Cheese Head,Hexagon socket head , etc.3 ... , Tin-plating, copper-plating, the wreath oxygen resin spraying, the heat disposing, hot-dip galvanizing, black oxide coating, painting, powdering, color ...