Vermont American 21768 Tap and Die Set, Red, 25-Piece Tap Taps: 8 to 10 threads chamfered for easy starting in tough materials Plug Taps: 3 to 5 threads chamfered for general use when tapping to bottom of hole is not critical (this is the most widely used type of tap) Bottoming Taps: 1-1/2 threads chamfered for use where thread must go to bottom of hole Heat treated and tempered carbon tool steel. Smooth, accurate threading Set includes 11 each taps and dies