MIBRO's Tap and Drill Bit Set includes the most popular tap sizes and the appropriate sized drill bits to ensure accurate threading. Taps are used to make internal threads to accept a screw or bolt. Made from quality tool steel with a titanium nitride coating for superior performance, these taps and drill bits have a smooth, hardened finish for ease of operation. The coating reduces friction and heat build-up, extending the service life of each piece.