Specification: Hexagonal/countersunk/frame/wafer head; drilling point; with/without wings Material: carbon steel C1022 Finished: galvanized (blue/white/yellow) Size: 5.5X25mm...50mm,55mm,60mm,etc. Length:13-150mm Usage: Self drilling screw is designed to fasten metal or other hard materials together Package: 25kgs/carton in bulk or as required