Torx countersunk head self-tapping screw is a tapping screw with hexalobular (Torx) recess and countersunk flat head. When screwed into workpiece, its thread can form matching internal thread directly without pre-tapping. The countersunk head sits flush with the assembly surface after tightening. Torx drive provides higher torque transmission and less cam-out than Phillips drive. Material: carbon steel, stainless steel; finishes: blue-white zinc plated, black oxide. Widely used for furniture, electronics, sheet metal and plastic assembly.