... Self-Drilling Screw 2.Material: carbon steel 3.Diameter: 4.2mm Truss Head Phil Self-Drilling Screw1) Standard: DIN, ANSI, ISO, GB2 ... ) Material: Carbon Steel3) Diameter: 4.2mm4) Length: 13-75mm5) Slot: phil6) Head: truss7) Thread: UNC, UNF8) Point: self-drilling9) Finish: plain, zinc, black ... advantage:"Fast delivery time, Reasonable price,The best service" Truss Head Phil Self-Drilling Screw