... .8,8.8,9.8..... DRYWALL SCREW,WOOD SCREW,CHIPBOARD SCREW. A good non-standard fastenerS ... tapping threads "A","AB", Threads for chipboard screw,wood screw,drywall screw;Type "M","UNC","UNF","BSW ... have special research person and more than 100 equipment to produce fastener.Perfect quality 1.The material ... of places such as drywall,concrete,chipboard,machine,wood...2) Main export market:North America,South ...