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re-cutting a 5mm thread?

This is kinda OT, but this group has more knowledge of small threads that any other I can think of.

I have a fairly-stripped, threaded hole (mudguard fitting eye, if you care) on my bicycle. If I tighten the bolt just-a-little-too-much is slips the thread.

It's currently 5mm. What can retap to to remedy matters?

I am aware that a "minor" retap to a different pitch would be a disaster, but the hole is quite shallow - probably only 4-5 turns, so minor pitch changes can be tolerated,

The alternative is to re-tap to a big enough hole to remove all the old threads, which I'd rather avoid.

So, can anyone recommend a thread with is similar (enough...) in pitch to 5mm, but slightly greater in OD?

BugBear

Reply to
bugbear
Loading thread data ...

There are none that I'm aware of. Helicoil it back to 5mm or drill and tap it out to 6mm are the options.

Reply to
Dave Baker

Can you not use a M5 screw and fit a nut on the back of the projecting thread, may have to be a traditional thin locknut if there is not room for a nyloc

Or 1BA is 5.3mm OD but about 28tpi

Jason

Reply to
jasonballamy

If you have access to both sides and plenty of clearance you could try a

4mm screw with a similar head not forgetting a spring washer under the nut.
Reply to
Neil Ellwood

I couldn't find a matching tap but this seems to show they may exist.

Hth,

Reply to
Boo

For a mud-guard eye, fill with braze, drill and re-tap.

Reply to
_

Sorry, I didn't give enough detail. The hole is in a braze on, on one face of a tube (so the bolt end ends up inside the tube) which is neat, tidy, and doesn't allow the use of a nut :-(

BugBear

Reply to
bugbear

That'd work, but require some respray afterwards.

But some kind of hard filler (perhaps epoxy) might buy me some time.

BugBear

Reply to
bugbear

Then you want a blind rivet nut!

Nick

Reply to
Nick Mueller

How about 7/32" x 32 TPI (5.56 x 0.79) - Tracy Tools offer one at £3. You'd have to make the screw though.

Reply to
Charles Lamont

M5 Helicoil or Recoil kit.

use stainless inserts for corrosion resistance.

Mark Rand RTFM

Reply to
Mark Rand
5mm is 0,8 pitch 1BA is 5.3mm and 0.9 pitch Those wankie American numbered threads have a #12 x 28 giving you 5.48mm x 0.907 pitch

John S.

Reply to
John S

If you can work it, a stud epoxied in the hole with a nut on the stud would likely hold.

Don Young (USA)

Reply to
Don Young

That's *most* interesting. Thanks.

BugBear

Reply to
bugbear

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