5C collet thread chasing die?

  • Thread starter Deleted member 43583
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Deleted member 43583

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I am looking for a thread chasing die to clean up and/or tune some 5C collet threads. The 5C uses a 1.238 x 20 thread.

My searching has come up empty handed thus far. Lots out there about using a split 1 1/4" x 20 but I would like to have the real deal.

Anyone found a source for a chasing die for this service?


John York
H-M Supporter - Gold Member ($25)
Jun 7, 2013
The fact that the collets are pretty hard and have a keyway may make chasing the threads somewhat problematic. To work effectively without hanging up, a die would need to have more than the usual four cutting edges, like six minimum, or even more. If there is one bruised threas, perhaps just grind the damage away.

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Jul 2, 2014
There are also no real standards that are actually followed for 5C collets. You will find loose ones and tight ones from different manufacturers, and also in different batches due to the alloy variation and heat treat. If the threads are simply dinged in a few places I would try a 20 TPI thread file to chase them with. If the threads are bad all over from something like being thrown into a box with other tools, then something like an adjustable pitch diameter hardened ring (and handle) with the correct 20 TPI internal thread with cutting teeth would be required. At some point, the collets are expendable and replaceable. Nothing lasts forever.
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