Sutton Carbon Hand Taps, UNC, Intermediate Lead. An Intermediate Tap is used after a Taper lead and assists in aligning and starting the tap into an untapped hole. 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.