... :4.8 ,6.8,8.8,9.8..... DRYWALL SCREW,WOOD SCREW,CHIPBOARD SCREW. A good non-standard fastenerS manufacturer for ... as :Self tapping threads "A","AB", Threads for chipboard screw,wood screw,drywall screw;Type "M","UNC","UNF","BSW"threads for ... in most of places such as drywall,concrete,chipboard,machine,wood...2) Main export market:North America,South America,Eastern Europe ...