Taps & Dies

2,000+ products

Expected delivery: Wed, Nov 18

Taps cut internal threads and dies cut external threads. Maintenance techs use them to repair stripped holes and chase damaged threads, and machine shops use them in production. This section covers hand taps in taper, plug and bottoming styles, spiral point (gun) taps for through holes, spiral flute taps for blind holes, NPT pipe taps, thread-forming taps, round adjustable dies, hex rethreading dies, tap wrenches, die stocks and tap and die sets. Threads include UNC, UNF, metric and NPT.

What to check before you order

  • Thread size and pitch. Confirm the exact size, for example 1/4"-20 or M6 x 1.0. Our thread sizes guide explains the callouts.
  • Hole type. Spiral point taps push chips forward and suit through holes. Spiral flute taps pull chips out and suit blind holes.
  • Tap drill. Drill the correct tap drill size first. Too small a hole is a common cause of broken taps.
  • Material. HSS taps cover most work. Cobalt or coated taps help in stainless and tougher alloys. Always use tapping fluid in steel.
  • Pipe threads. NPT taps are tapered, so tap depth controls the fit.

Common questions

What size drill do I need for a 1/4-20 tap?

A #7 drill is the common choice for about 75 percent thread engagement in a 1/4"-20 hole.

See drill bits, the Alfa Tool line, and all cutting tools.

Taps & Dies: page 21

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