British Airborne Trailer Wheel Nut Thread Dims ?

[roajeep]

Hi,
According to an Illustrated Parts List I have, the Wheel nuts and studs have a 3/8 inch BSF thread; but when in UK recently I bought a 3/8 BSF tap and die to use to clean threads, they turned out to be far too large. I can slip the die over a Wheel stud and it barely touches. So I wasted quite a bit of cash.

Does anyone know what is the correct size of thread ?

The trailer, brake drums, and wheel studs are original. There's no doubt about that.

Thanks.

[Blackpowder44]

having just checked 6 of my spare wheel nuts for the British 10 cwt. trailer and found that they are all 3/8 in. 20tpi BSF I am at a loss as to why you have the wrong die thread, John.

[roajeep]

Thanks for yr confirmation, John. I'll check again. It may be that the store in UK sold me tap/die with incorrect markings.
But at least now I am certain what i must get.

BTW anybody reading who knows of an early type rear pintle hook for an AB trailer for sale, pls contact me.

Thanks,

David

[ian]

mabe the thread is 3/8th UNF did anyone think about that
i
have seen maney manuals that heve not been updated ,,and ive seen maney RR metiore engine blocks ruind becouse of the thread missunderstanding

BSF and UNF are not close inof threads ,not like UNC, and metric course ,in the larger sizes ,which wil at a push fit
if the thread /nut /bolt fit for less than 1 half to 1,1/2 turn then the threads are wrong ,, get a thread guage and check

[Blackpowder44]

Ian, please read my post again, I took 6 of my spare wheel nuts and tested them with a 3/8 th/ BSF tap asI specifically stated so your post is just mudding the water, John.

[roajeep]

Hi guys and thanks for yr replies.
Actually turned out to be a false alarm. The inner threads of the nuts were rusty but when I used a 3/8 BSF tap vary carefully it fitted correctly and after a bit of juggling to and managed to clean the threads without causing any damage.
David