High speed steel ground threads tmx hand tap with straight flutes – available in three chamfer styles: taper chamfer has 8-10 thread chamfer length, plug chamfer has 3-5 thread chamfer length and bottoming chamfer has 1-2 thread length. 1/4 – 20 oversized h13, plug chamfer, hss hand tap, ground, rh, 4 flutes. hand taps are used in a variety of machining applications as well as by hand