Truss/Button Head Machine Screw with Zinc Plating and Length Ranging from 13 to 300mm Head type: CSK/flat head, truss head, trumpet head, wafer head, pan framing head, pan wafer head, hexagon head, pan headThread type: type A, B, C, high-low, double thread and other special threadLength of thread: 13 to 300mmHead recess: Philips 4 Ribbs, Pozi, Philips, Square, H.W.F undercut, H.W.H, serration, ...