1) Material:Low carbon steel, Alloy steel and st. steel(A2/A4) 2) Surface: Plain, Zinc plated(Cr3 and Cr6), Yellow zinc plated, black oxide, black Zinc plated, Hot Dip Galvanization, Decromate, ruspert.3) Drill hole, forms mating thread and c operation. No more need of difficult alignment of two or more elements.4) Eliminates power drill, drill bits and elaborate and costly press tools, machine taps and their maintenance. Only one tool required - The screw drive.5) Ensure correct hole size every time, resulting in better thread engagement and tighter clamp.