Uniburr thread recovery tool...

[Erich]

I should have it next week Ruairidh. About $80 +, so not cheap. But if it saves time and makes a cleaner chamfer, I'm all for it.

Erich

[Ruairidh Dunford]

Thank you Erich - please do report back.

[John Mason]

In the past I have over come this problem of burred threads on the end where they start by getting a spare nut with the same thread. Cut this nut in half then place both halves on the good parts of the threads and keep them in place with the correct size ring spanner. You will see that the nut halves fit together with the saw gap at each side.  Wind of the nut halves with the ring spanner And as it gets to any burr it will straighten up the thread allowing a new full nut to be started and wound down the thread.
I have used this method successfully on a number of things including Austin Seven crankshaft. I cannot claim it was my idea this was given to me by an old mechanic who if still alive would would be about 110 years old.

[Erich]

As promised, here is my review of the Uniburr. It is brief as I spent the last couple of days insulating my garage after getting tired of cold hands and feet. I ordered the Uniburr Plus # 1816. I used it on a 5/8 hot dipped galvanized carriage bolt. Obviously not hardened steel. The specs say that it is good for grade 2, grade 5 and grade 8. Also stainless 300 Series. But not US Grade ASTM-A574. The literature says," Real men don't need instructions and as a result, many a young brave young Uniburr will die". You have to use this at a very slow speed. No reverse. And the harder the metal the more pressure is needed. On the carriage bolt it worked well. I will note that because of the angle of the cutter head, you will lose a half dozen threads, so that if your bunged threads are on a bolt that is barely long enough for the application, you may not have enough threads left to fix a nut. In that case, cleaning the threads with a die or thread file would be more advisable. Do I like it it? Yes. Will I use it again? Certainly. With fairly critical, as far as length is concerned, studs and bolts, I would probably clean up with a die.

Erich in Seattle

[Ruairidh Dunford]

Thank you for taking the time to do that Erich - much appreciated.

[Erich]

Ruairidh, you are most welcome. It is certainly a good tool to have. I should mention that depending on how badly the threads are bunged, you might not lose so many. In my particular case, the threads were flattened on the old bolt for about 3/16 of an inch from the end so I had to take a fair amount of meat off.

Erich

[Dave Wortley]

Couldn’t find the price on the link or even the item. File a chamfer and use a dienut?

[Bob Culver]

To think that for decades  I have laboriously filed threads with miniature diamond shaped files etc and all i needed to do was shorten the bolt!

Die nuts and fixed dies have a nasty habit of starting out of step; the ideal is two piece dies applied as John suggests.

The handbook for a family car showed a hub puller and thread protector. As nothing pulled on the thread I could not see the reason. I did not have proper puller so cobbled a giant one from other old hubs for which I did have a puller. It all came apart with a bang. I spent a morning fixing the thread where it landed!