A4 stainless nuts: thread #12-24 UNC?

[nigelmercier]

I need a few A4 stainless nuts in what I believe is thread #12-24 UNC. Any suggestions where to buy?

 

[Hypocacculus]

It's a U.S thread standard so you could try looking at suppliers across the pond. Alternatively, BSW Whitworth is extremely similar.

 

[rogerball0]

www.inox.ie

They supplied me with a few lengths of 3/4" AND 1" A4 UNC studding and the corresponding nuts for me to make a new set of keel bolts for my Centaur.

At the time (2009) local suppliers wanted 850 quid whilst the above supplier bought it in from the U.S. via Ireland and even with Irish vat (21%) i got everything for around 300 quid.

Just checked and they're still going, i think i dealt with the Birmingham branch for my order.

 

[Plevier]

Try http://www.namrick.co.uk/ they can often supply stuff that isn't listed on their website.

 

[David2452]

Here you go.

http://www.stainlessautomotivefastenings.co.uk/index.php?main_page=product_info&products_id=6594

 

[nigelmercier]

Alternatively, BSW Whitworth is extremely similar.

Now you've worried me. It is definitely 24 TPI, but the major diameter is slightly under what I expected for a #12. The OD of the screw should measure 0.2078" to 0.2150", it measures closer to 0.200"

[Later] Just checked, a BSW with 24 TPI had a MD of 0.1875"

Just found a really handy document: http://www.gerardsgarage.com/supportfiles/Threading_Tables.pdf

 

[prof pat pending]

So it could also be a 10-24UNC with an MD of 0.19 then?

 

[nigelmercier]

So it could also be a 10-24UNC with an MD of 0.19 then?

Arrgh! Possibly, I hate imperial threads!

 

[prof pat pending]

You need someone with a set of thread gauges

 

[David2452]

You need someone with a set of thread gauges

Or a nice big box of nuts

 

[nigelmercier]

You need someone with a set of thread gauges

I've got a TPI gauge, and a digital calliper. Is there something else?

Actually the gauge is the best I've found, so worth sharing: http://www.ebay.co.uk/itm/291152865177

 

[prof pat pending]

There is, but that should do you

So when you measure the TPI does the angle of the threads match the gauge?

What sort of vernier do you have?
What is the OD of the thread?

 

[Heckler]

It's a U.S thread standard so you could try looking at suppliers across the pond. Alternatively, BSW Whitworth is extremely similar.

Uh! If you are going to pronounce on things then make sure that you know what you are talking about.
unified threads took over from bsw and bsf here in the late 60s and early 70s then we went to metric. Unified thread stuff is still easily available HERE. Trying to use whitworth threads on unified thread stuff is just plain stupid! It doesn't fit! (There is one exception, 1/4" iirc) different thread angles, different tpi
Stu

 

[Hypocacculus]

Uh! If you are going to pronounce on things then make sure that you know what you are talking about.
unified threads took over from bsw and bsf here in the late 60s and early 70s then we went to metric. Unified thread stuff is still easily available HERE. Trying to use whitworth threads on unified thread stuff is just plain stupid! It doesn't fit! (There is one exception, 1/4" iirc) different thread angles, different tpi
Stu

I assumed that the OP had already tried and failed to get the stuff "HERE" - why else post to a forum and why are you so snappy about a suggestion that is still valid?
My suggestion of Whitworth is because the threads are very similar and the OP wasn't entirely certain what thread he had.

View attachment 43411

 

[nigelmercier]

So when you measure the TPI does the angle of the threads match the gauge?
What sort of vernier do you have?
What is the OD of the thread?

I think the angle matches the UNC gauge, although not 100% certain.
Callipers: http://amzn.to/TdfiC3
For OD, see #6 above.

 

[prof pat pending]

If you hold the thread up to the light, and sit the edge of the gauge on the centerline of the thread, you should get a good idea, although you are looking at 2 thread profiles which are very similar.

As for the thread dia, which side of 0.2 is it?
Use the wider section of the jaws to measure, don’t put too much pressure on the vernier