A cheeky/optimistic request - 7/8 20 tpi die?

This is a bit cheeky considering none of you know me yet...but...I need a 7/8" 20tpi die (BSB?) to repair the thread on a shaft of my mill restoration. Tracy Tools have the taps and dies but I can't really afford to buy them for just one quick job.

Would any of you guys have one I could borrow? Obviously I'd cover the postage costs (both ways) and love you forever

Sorry about the sheer nerve...but I'm a wee bit desperate.

I will look in my workshop tomorrow, I do have a selection of odd ball stuff. Will PM if I find one.

That's greatly appreciated, Chris

Do you really need a die or would a thread chaser be sufficient? A location might help, too. There might be someone local.

His intro thread gives his location as Newcastle/Durham......oop north then....

Ordinarily a thread chaser would probably do. But there's a part on the thread where an old pin is and that's stuck tight. So it'll need cut through. Also it's on the machine already which means no more bashing to get the pin out.

I'm in the North East between Durham and Newcastle.

OP should be read BSC (British Standard Cycle).

Are you sure? I work on old cycles with BSC threads a lot, and 7/8" should be 24 tpi.

7/8 x 20 is however a UNEF size.

Edited By David Standing 1 on 13/09/2017 18:36:47

Tracey Tools refer to 7/8" x 20 as cycle thread, presumably where the OP is coming from.

if the pin area is the only problem, I wonder whether a small triangular file could be used to dress out the remains of the pin. The thread angle seems likely to be 60 deg.

Yeh, TT calls it BSC: **LINK**

The threads measure 20tpi on my cheapo gauge, which I don't really trust...but it is.

The threads are just rounded a bit, not crossed, and I'll likely flatten the pin area to accept a grub screw instead of the original pin.

Would it not be weird to have a unf/unef thread on a late 50s UK machine which uses Whitworth for the most part?

Yes, that's odd - Tracy Tools show two BSC pitches, 20 tpi and 26 tpi. All the cycles I have worked on are 26 tpi, 20 tpi is a new one on me!

If it is a British machine, yes!

Exactly. This thing has some weird threads, though. The pipework uses 26 tpi BSC which I had a friend tap an oil part as like now...I really didn't want to buy a use once part . BSP was well in use at the time of manufacture, and it even uses BSP in places! Ha!

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Once you get above a certain size you get an alternative of 20 from the normal 26. Pedal threads have always been 9/16" x 20 RH and LH

Chances are that I do have one, I have a full set up to 1" in RH and LH threads but I can't check as I'm off work for a while.

Can you use a thread file or at worst a small triangular file

Still, it's looking beautiful, so can't be mad with it.

No thread file atm. But I could always borrow one. Would rather clean it up with a die.

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