Hex Head Self Drilling Roofing Screws 1)Standard: DIN, ASTM,AS,GB 2) ... 3)Diameter:3.5mm~6.3mm,6#~14 Hex Head Self Drilling Roofing Screws 1)Standard: DIN, ASTM,AS,GB2)Material ... head,truss head,hexagon head,round head,oval head in cross recessed,combined,torx,slottedThread Codefull thread,half thread,or nonstandard ...