Australopithecus scobis wrote:
Greetings,
Recently someone here pointed out that hexagonal dies are for
rethreading and that the OP needed the round die for his
threading application.

Are there also two types of taps, threading and rethreading?


As for taps, not to my knowledge. It's a good use for taps that are
already too worn to cut new threads dependably. The rust and other gunk
typically on a used thread wears a good tap or die considerably, thus
it's not advisable to use them for this purpose if you don't have to.

As for dies, it USED to be that hex dies were for rethreading. Rethread
dies are the same size as the common nut for that size thread, and can
be turned easily with the same wrenches. Their proportions are thus
'fatter' (thicker with smaller diameter) than a standard die.

Now there are hex dies intended for primary threading. These are usually
at the low end of the quality spectrum, and mostly sold at hardware
stores and home centers. These hex threading dies are larger than
rethread dies, about the same size as regular round dies, and about the
same thickness. Thus they are more 'plate like', larger diameter and
thinner in proportion than rethread dies.

Dan Mitchell
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