... screw,drywall screw;Type "M","UNC","UNF","BSW"threads for Machine threads.Head typesHexagon head,Mushroom head,Pan head,Countersunk head ... a 20 GP container :22.6T-25.5Tadditioal processes Washer assembly,Heat treatment,Baking hydrogen,Anti-slipping patch can be proceeded ... used in most of places such as drywall,concrete,chipboard,machine,wood...2) Main export market:North America,South America,Eastern ...