checking dies

[Chris KC]

Jon, well worth pressing those thread gauges into service!

Most of the stuff you are likely to encounter is covered here:
https://britishfasteners.com/threads/bsf.html

There are of course some very similar threads between some of the systems which may catch out the unwary, and not always easy to identify by measurement. A thing I've occasionally thought of doing but never quite got around to is to have a 'master' sample of each in the workshop as a means to physically check random fasteners I find in jam jars etc.

Supplies of good BSF/ BSW fasteners are not what they once were and it has to be said quality is variable. If 'recycling' then all manner of things are possible.

Nick, by all means clean up damaged threads but I'd take care to remove as little material as possible especially on hub studs. The old brass A7 wheel nuts easily strip or work loose and need regular checking. For 'faster' cars steel Nylocs and penny washers are a sound idea. Sorry if teaching to suck eggs...

[JonE]

on a specific, having problems with 5/8 16TPI axle stubs... presumably the distinctive castle nuts which fit the front axle are unlikely to be anything else, or is that not others' experience? I have a number of nuts and many don't want to go on the most original looking of the stub threads. And the stub that looks like it has been cleaned up...I wonder what it's been cleaned up with - perhaps a 14TPI BSF? Would the difference between 14 and 16TPI provide 'ambiguity' and perhaps permit either to fit if forced?

[Ian McGowan]

...I wonder what it's been cleaned up with - perhaps a 14TPI BSF? Would the difference between 14 and 16TPI provide 'ambiguity' and perhaps permit either to fit if forced?

Wishful thinking I fear, Jon 

Why not buy a front stub-axle castellated nut from any of our cherished suppliers and use that as your "standard". any stub axle that doesn't fit that is either not an A7 or, its been buggered about with!!

Sadly, the world is full of people who are capable of "cross-threading" even parts that would normally unite without problem; let alone force 14TPI and 16TPI to mate as it were.

[JonE]

I've got 4 or 5 nuts that are correct (as I can cross check the larger rear nuts and also the ones on the radius arms). It just isn't quite so easy though with a stub axle that is otherwise completely ok. I've sacrificed a nut to retrain the thread stub axle and will go back to the closing tool shop and seek a UNS die....

[Ian McGowan]

" will go back to the closing tool shop and seek a UNS die...."

Quit whist you are ahead, Jon.

[Chris KC]

Dave Cochrane sells the correct die for the stub axles I believe, that would be your best bet for cleaning them up.

[JonE]

" will go back to the closing tool shop and seek a UNS die...."

Quit whist you are ahead, Jon.

well what IS the correct tool designation/thread type? The Cornwall site just says 'special', and I don't want to have to buy something new if I can use something secondhand locally.

[Steve Jones]

It is a special. As above, David Cochrane sells the correct tap and die. I've had one for many years. I rarely use it but when I do, it's the only thing to use. The thread is an Admiralty Thread. Used on stubs, half shafts and crankshaft/starter dog. Best of luck with finding one anywhere other than DC.

Steve

[Howard Wright]

Hi Jon

A die is the best solution but if you had a lathe you could use a thread chaser or if the lathe boasted screw cutting facilities just clean the thread directly in the lathe (with a suitably sharpened cutting tool).

My lathe is very old, relatively cheap but I’ve used it to cut and clean threads.  Notably to make a pinion flange locknut.  I seem to remember that that was 20 t.p.i Whitworth form.

Cheers

Howard

[Henry Harris]

https://www.tracytools.com/taps-and-dies...ct_id=1108

Tracy tools can supply all you need.