Author Topic: SALVAGING A DAMAGED THREAD  (Read 627 times)

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Offline Brooklands

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SALVAGING A DAMAGED THREAD
« on: November 28, 2011, 09:35:11 pm »
Remember the mixed emotion of successfully undoing a tight nut, only to find that some of the thread came with it, or finding a good stud with the end battered or half rusted away ? A new nut usually won't start or cocks over, cutting a new thread with a die may not match with the good thread further down the stud and cuts half of it away, and filing is by no means easy or successful.
For those of you with a priceless set of dies look away now.........  I came up against the problem of a wheel stud which had a battered end that stripped the nut thread on the way off and would have involved a lot of work dismantling the whole hub assembly to remove the stud, for which I had no replacement.
Step 1 is to find a matching die (the cheapest in your box), preferably a split one. Step 2 is to grind a groove on the outside of the die opposite the split to a point where there is about 1/2 mm of metal left. Step 3 put a screwdriver blade in the split and gently lever open the die and it will break neatly into 2 halves. Keep the halves the same way up.
Step 4 put the die holder over the work and wrap the 2 halves of the die around the good part of the thread and tighten the die holder lock screw gently onto the original split in the die - the crack opposite will close up and the two halves of the die will be locked. You can just see the crack in the photo.
Step 5 wind the die up the thread, re-cutting the damaged area from the bottom up and providing a new (albeit not always  pretty) starting thread.
The item in the photo is just a thread I battered with a hammer so that the nut wouldn't go on. If access is poor you may even be able to hold the two segments together with a jubilee clip and re-work the thread by hand.
Joe
Norfolk 'n good!