• Double countersunk head reduces the likelihood of head shear and assists completion of countersinking • Partially threaded from 1 1/4” 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">