off: imperial helicoil inserts

Just use UNC helicoils - it's effectively the same as UNC and for all normal purposes the threads are interchangeable. I'd do it for you but posting to New Zealand is unlikely to be cost effective.

Whit Helicoils and kits are still available. All the larger engineering supplies people (e.g. Cromwell Tools) will be able to help.

The problem with retaining the Whit thread is that your expensive kit may never get used again. A UNC kit has a greater chance of finding another application and tends to be cheaper size for size.

In article , Dougal writes

Thanks everyone who replied.

I think you're right Dougal: a few web searches on UNC and/or Whit inserts indicate that it's about £60+ for the two threads. Whilst it's true that'll do about a dozen threads, it's a lot to stump up for the two I need to do at the moment.

Further research indicates that there are some re-threading specialists in the area, so I'll investigate that too.

Once again, thanks for the inputs.

Regards,

Simonm.

Whitworth and UNC are interchangeable for practical purposes in the sizes mentioned.

JD