Extension, nut, and pulley taps are longer than standard taps and can thread deep holes and access holes that standard taps cannot reach. Extension taps have long shanks and are used for general purpose tapping applications. Nut taps have long, slender shanks that nuts can slide onto after they have been threaded by the taps. Pulley taps create internal threads in set-screw holes on pulley assemblies. Their shank has a diameter that is roughly equal to their thread diameter, and the shank acts as an alignment guide as the tap reaches through the pulley hub to access the set-screw holes.