A traditional twin-thread woodscrew with single lead start for a fast installation. Roundhead screw used for clamping to flat surfaces or to achieve a high aesthetic finish. NOTE: Partially threaded. Partially threaded from 1 ” and above.Made from C10-18 steel to ensure consistent quality.60° twin-threads with parallel shank for faster insertion and greater pull-out resistance .Surface hardened up to 750 HV to prevent torque shearing under load and a core hardness of up to 450 HV for improved ductility.25° sharp point and single lead for a fast start and improved thread acceptance.