Fractional Tap, National Coarse Thread, 9/16-In. x 12

9/16″ x 12, national course thread, fractional tap, carbon steel, ideal for routine maintenance, repair work & for rethreading where high accuracy & tolerance thread is not critical, straight flutes are ground to provide rapid chip removal for efficient threading, designed for hand threading work in a variety of materials taps produce a class 2b thread, use 31/64″ drill bit.