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18pr Fuze thread size

Gspragge

Well-Known Member
Premium Member
What is the 2" thread size for the the No 80 fuzes tap & Die. A friend wants to hunt
such a thing down. But I need to know what the proper designation is.
 
the taps shown in the pictures on that website aren't 2'' and 28 pounds seems a bit cheap for a tap as big as 2''?
 
the taps shown in the pictures on that website aren't 2'' and 28 pounds seems a bit cheap for a tap as big as 2''?

£84 for a HSS tap, I guess £28 tap will be carbon steel, ok for thread cleaning. I think the picture is a generic picture, not of the actual 2" tap. There are a couple on ebay for around £50, in uk and Australia....

Cheers
Gary
 
yes you will have to be careful with a carbon tap as it may chip or break the cutting threads if you push it too hard.very slowly with lots of cutting fluid should do it
 
I'm not sure it's Whitworth.

From memory it is 2" x 14 TPI BSP (British Standard Pipe). It could be BSC - Conduit, I can't remember off hand without checking. It's quite a hard thread size to get.

I borrow a friend's taps and dies to clean up fuzes and sockets.

I think if you look up Whitworth sizes it's not 14 TPI for 2" size.
 
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What you need to know to match threads is: form, ie Whitworth, metric, unified as this gives the angle and shape of the grooves and ridges, then diameter, then pitch ie how many threads per inch or distance between in mm. Because you can have the same dia and pitch with different forms some of which will not go together and you can have standard pitches for a give form and diameter and special pitches for the same form and dia. Virtually all countries ammunition threads are non standard pitches for their diameter.
 
I guess the best way to find out for sure would be to send the tool company a fuse adapter from, say, an 18 Pdr Shrapnel and ask them to check it with a screw pitch gauge.
 
As TimG stated in post #2, it is 2" x 14 tpi, Whitworth form.

Specifically it is 2" x 14tpi British Standard Conduit - one of the family of Whitworth form threads.




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Hi all,

Further to the discussion on British 2" GS thread size for 18Pdrs, 6", 8", etc, I recently sent off an 18Pdr adaptor to Tracy tools to match the thread size.
It was confirmed as being a 2" x 14 tpi Whitform BSC (Conduit) size, as other members here have mentioned. I took delivery of the tap today and it fits perfectly.

It cost 35 quid plus VAT, (Carbon Steel), and restores knackered threads back to perfection.
A very good quality piece of kit and superb customer service.

(I don't work for the company btw....)

I had 3 9.2"s struggling to take a fuze of any type due to poor threads. Now all are perfect. The bonus was I was offered a 'cut price' new old stock surplus tap wrench for the tap. When it arrived, I found it dated 1945...
Cheers.










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That thin die nut shown by Snufkin is what I need. I use a 4 cutter pipe threader and turn the fuzes by hand to clean threads.
2" x14 Conduit. The 2 taps I use seem about 1 thou oversize- or the military cavities are a bit undersize and I need a 24" shifter to clean and retap damaged projectiles. I had a custom bottom tap made a few thou undersize and is great for cleaning star shell threads etc. or light rust and damage.
It has to be hardened of course.
I use a tap 1.700"-14 UNS zone 4 that I found at a swap meet for $25 to clean all 105mm threads without fuze adaptors. A bottom tap I was lucky to find.
I also found a Starter tap marked 6Pr HE Shell Mk1T dated 1968 MO. It fits 6Pr and 76mm ARMC which are 14 TPI. Look out for them.
 
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