Mystery wheel stud thread

[TheBrick]

I have an old car / plant trailer. A few of the studs are damaged and one looks like it may need to be cut off to remove wheel. I would like to replace them but they seem a odd aize

Upon removal of a net the best match on my thread gauges is 16tpi. 1.5 mm is the closest metric but the 16tpi definitely fits well. The studs appear to measure 22.5 - 22.7mm with a Vernier. That translates to very close to 7/8".

All the thread tables I have found show unf 7/8" at 14tpi and 3/4" at 16tpi. 3/4" = 19.5 mm. I have measured both thread and stud several times.

I must be missing something simple. Any ideas please?

 

[TheBrick]

P.s. I just tried a 55degree whitworth gauge and 16tpi fitted best again but I fancy the 60 degree 16tpi was better

 

[Agroshield]

It does not help much, but everything you say above is correct.

7/8" BSF (Whitworth form) is 11tpi so it is not that either.

It looks like 7/8" - 16 exists as a UN thread (https://www.gewinde-normen.de/en/16-un-thread.html) so in that respect, it is a possiblity.

 

[TheBrick]

That is a good link thanks. I couldn't find it listed as a possibility on my usual sources.

 

[RWD3M]

Ok, daft question time, that 22.5 - 22.7 is the major diameter of the thread and not the AF of the nut, right?

7/8" is a heck of a big ole thread for a wheel stud. Commercial vehicle territory!

If it is, then UNEF it is as @Agroshield says.

 

[bourbon]

How old is the trailer and is it a recognized manufacturer?

 

[TheBrick]

22.5-22.7 is the strud, so major diameter. Yep its a big heavy 3.5t trailer. 24mm socket was the best fit.

 

[TheBrick]

How old is the trailer and is it a recognized manufacturer?

No plate I have seen. As for age again no idea.

 

[Erie Fred]

I had a 1986 Izusu NPR cabover truck, 2 ton, 16" wheels, that I think the studs were about that big, lugnuts
had to be 1 1/8" at least.
And half of them were left handed......

 

[Agroshield]

If it is, then UNEF it is...

...except I did not say that and it is not that.

7/8" UNEF is 20tpi.

 

[Johnnybravo]

22.5-22.7 is the strud, so major diameter. Yep its a big heavy 3.5t trailer. 24mm socket was the best fit.

Something doesn’t add up here…22.7mm stud in a 24mm hex… Nah…

 

[bourbon]

Post a picture of the whole trailer, Someone on here might recognise what it is.

 

[RWD3M]

...except I did not say that and it is not that.

7/8" UNEF is 20tpi.

Is it not?

Edit: How odd, Wikipedia gives it as 20 TPI as you say.

 

[mr haynes]

Something doesn’t add up here…22.7mm stud in a 24mm hex… Nah…

Would be looking at something like an m16 or 5/8 with a 24mm spannered nut

 

[TheBrick]

Will try to post pics later. Socked size was from memory.

 

[Erie Fred]

Post a picture of the whole trailer, Someone on here might recognise what it is.

My money is on ex military.

 

[Agroshield]

Wikipedia gives it as 20 TPI as you say.

Yes. Sorry. It must be typo. on the German page. You can see from the screenshot that what is shown is a 16tpi constant pitch series, which UNEF most surely is not. I will drop the guy an email and let him know.

 

[TheBrick]

Something doesn’t add up here…22.7mm stud in a 24mm hex… Nah…

Hang on You're right I think dyslexic Dave has been at it again and I have read the main scale wrong. Will update with whatever stupid mistake I made after dinner. I wonder If I read backwards on the main scale, I thought something was up initially. I read the Vernier multiple times, but I think I must be off somewhere else.

 

[Agroshield]

I read the Vernier multiple times, but I think I must be off somewhere else.

I do not know if it might help, but 22mm copper pipe is 22mm OD. So you might be able to do a comparative measurement with that or some other known object. That's what I do when the battery on my calipers goes flat.

Another near-enough measuring thing is one of these:

https://www.amazon.co.uk/Helix-Circle-Stencil-Template-Translucent/dp/B00290KWWA

 

[TheBrick]

Yes I am ****. 12.7 not 22.7mm so 1/2" 16tpi which is BSF threads it would seem! Oddly the 60degrees guage seems to fit slightly better.

Thanks for entertaining this idiot, you may mock me as I slap my own face!