Sutton Carbon Hand Taps, G Series BSPF, Taper Lead. Cuts internal threads in pipes and are ideal for pipe fittings. A Taper Tap is used for starting a thread prior to using an intermediate or bottoming lead tap when the material is difficult to work.Recommended for small diameter threads. Made from Tungsten Chrome Alloy these taps are ideal for routine maintenance, repair work and for rethreading where high accuracy and tolerance thread is not critical in general purpose applications, non-ferrous metals & plastics.Straight flute taps are only suitable for hand operations, tapping up to 1-1/2 x diameter.