Ideal for general purpose threading, the Hanson 3/8 in. – 16 NC Tap and Letter "O" Drill Bit Set is a convenient HCS tap and HSS drill combination. The high-speed steel drill bit ensures fast, accurate drilling, while the self-aligning tap works great with through holes and irregular surfaces. Set includes 3/8 in. – 16 NC Tap and Letter "O" drill bit.