Drywall screw mostly bugle head to help the screws stay in place without tearing all the way through the drywall

Coarse thread, fine thread, twinfast, thread type 2A
Twinfast thread with high quality request of drilling speed.(within 0.5 second - 15KG/2500RPM/0.6MM steel plate)

Size : M3.5~M4.8     
Length : 13~150mm

Surface : Phosphate(black, gray, dark gray),

Zinc plated(Cr3+/Cr6+/clear/white/yellow)