... ,drywall screw;Type "M","UNC","UNF","BSW"threads for Machine threads.Head typesHexagon head,Mushroom head,Pan head,Countersunk head ... type,Torx type,trangle type,slotted point type,square type,Combined type...FinishZinc plated,Nickel plated,Dacroment Plated,chromium plated,Tin ... used in most of places such as drywall,concrete,chipboard,machine,wood...2) Main export market:North America,South America, ...