Metallics 112CTT Carbon Steel Tap Taper Type 1-12 (1pc)

The 112CTT cuts a 1-12 thread, meaning a 1 inch nominal diameter at 12 threads per inch. That is the UNF (fine) pitch for 1 inch, not the 1-8 UNC coarse thread, so check which pitch your rod or fitting uses before you cut. Pick the matching 1 inch tap drill for the hole.

A taper tap, which is what the Metallics 112CTT is, has a long lead chamfer over several threads so it self-aligns and starts easily by hand. That makes it the one to reach for on through holes and on rod ends. A plug or bottoming tap has little or no lead chamfer and is used to carry threads to the bottom of a blind hole after a taper tap has started it. For most electrical and mechanical support work with through-drilled steel, the taper type is the only tap you need.

Carbon steel. That suits occasional hand tapping and chasing damaged threads in mild steel, aluminum, and brass on the job, which is what most electrical and MRO rod work involves. Carbon steel taps run cooler and softer than HSS, so keep hand speed down, back off to clear chips, and use cutting oil. For repeated production tapping or hard alloys, an HSS tap holds an edge longer.

Yes, for chasing 1-12 fine threads. The taper lead on the 112CTT lets it pick up existing threads without cross-threading, so it works for cleaning rust, paint, or burrs out of a 1-12 tapped hole or coupling. It will not clean a 1-8 coarse thread; the pitches do not interchange, and forcing it will wreck both the part and the tap.

One tap per order, supplied in a pouch. If you are kitting multiple techs or want a spare on hand, order the quantity you need rather than expecting a set.

Metallics part number 112CTT. The number reads as 1-12 Carbon steel Tap Taper, so the series logic carries the thread size right in the designation.