Simpson Quik Drive QRS3 50 Bulk Bits #3 Square Drive 50 Count SJC MSJC Steel Joist Connectors Hard Metal (HW) Carbide Construction Hard Metal (HW) Carbide Construction the tungsten carbide tool material maintains a sharp cutting edge through high volume production runs Purpose built for hinge and lock mortising the negative shear angle and thick carbide tips work together to produce the flat bottoms and clean edges that hinge mortising demands reducing project interruptions and keeping the correct bit available across extended driving sessions or multiple jobs The Simpson Strong Tie QRS3 50 Bulk Bits #3 Square Drive 50 Count is a professional grade replacement driver bit pack designed specifically for use with the Quik Drive auto feed screw driving system