Unusual Thread Type?

[File HandleParticipant @filehandle]

Posted by Grindstone Cowboy on 25/08/2023 14:34:57:

My tap also arrived this morning, Martin, thanks again

Rob

As did mine, many thanks for your generosity also.
Keith

[SillyOldDufferModerator @sillyoldduffer]

Posted by Oily Rag on 22/08/2023 18:24:22:

Martin – I have sent you a PM.

These taps are, I suspect, as used in some BSA gunsight mechanisms.

Could be. The gun-trade is notorious for non-standard threads and somebody had to make their weird taps and dies. Even government arsenals misbehaved – the Enfield Inch was 4 tenths shorter than the inch used by the rest of British Industry. And the US inch was bigger than the biggest British inch.

Dave

[old martParticipant @oldmart]

I have a tin full of special taps at the museum, kept hidden lest somebody mistakenly use one. They have accumulated from tool boxes donated over the years. Every one a special, designed to do a single thing better than an off the shelf size, and much too pretty to chuck in the bin.

[David LindquistParticipant @davidlindquist71920]

Posted by peak4 on 21/08/2023 22:32:21:

Posted by larry phelan 1 on 21/08/2023 18:44:33:

Whitworth fine ????? That,s a new one for me !

I too assume that WF in this context is probably Whitworth Form, but when Joseph Whitworth came up with his thread dimensions, it wasn't a British Standard, though obviously later became one, along with a fine thread to become BSW & BSF, so perhaps there was a Whitworth Fine before the BS was added.
I can't find when the finer thread form was originally started.
There's an interesting article on The History of Whitworth here, which includes some info on the origin of the spanner sizes.
http://www.team.net/sol/tech/whitworth-hist.html

Interestingly JW himself proposed a thread series based on decimal, rather than fractional, which did include a 0.2" diameter, though that was in 1897, which rather predates those taps by the looks of it.
https://en.wikisource.org/wiki/Miscellaneous_Papers_on_Mechanical_Subjects/A_Paper_on_Standard_Decimal_Measures_of_Length

Bill

Edited By peak4 on 21/08/2023 22:33:38

Clicked on the History of Whitworth and was a bit put off by the author airily stating "I forget his first name right now." It's Joseph for heaven's sake. Just as it's Henry Maudslay, James Nasmyth, William Sellers or Joseph R. Brown. If I were to cite any of the great 19th mechanicians and forgot their first name, I'd make it my business to look it up.

And the assertion that the US standardized on the BSP system for pipe threads is, well, wrong. We use NPT which has a different form, 60 degree vs. 55 degree and while the pitch for same trade sizes is the same for BSP and NPT, for other trade sizes it's not.

David

[Bill PhinnParticipant @billphinn90025]

Posted by David Lindquist on 27/08/2023 21:55:26:

 

Clicked on the History of Whitworth and was a bit put off by the author airily stating "I forget his first name right now." It's Joseph for heaven's sake. Just as it's Henry Maudslay, James Nasmyth, William Sellers or Joseph R. Brown. If I were to cite any of the great 19th mechanicians and forgot their first name, I'd make it my business to look it up.

David, it's a random Internet page on Whitworth cobbled together by an enthusiast whose enthusiasm for the topic clearly stopped short at looking up Whitworth's first name.

If it were a printed book issued by a reputable publishing house then the writer's indolence would be far more surprising and less excusable.

Edited By Bill Phinn on 27/08/2023 23:11:46

[David LindquistParticipant @davidlindquist71920]

Posted by Bill Phinn on 27/08/2023 23:11:13:

Posted by David Lindquist on 27/08/2023 21:55:26:

Clicked on the History of Whitworth and was a bit put off by the author airily stating "I forget his first name right now." It's Joseph for heaven's sake. Just as it's Henry Maudslay, James Nasmyth, William Sellers or Joseph R. Brown. If I were to cite any of the great 19th mechanicians and forgot their first name, I'd make it my business to look it up.

David, it's a random Internet page on Whitworth cobbled together by an enthusiast whose enthusiasm for the topic clearly stopped short at looking up Whitworth's first name.

If it were a printed book issued by a reputable publishing house then the writer's indolence would be far more surprising and less excusable.

Edited By Bill Phinn on 27/08/2023 23:11:46

Yes, looking at this I was a bit churlish and I apologize to the forum.

Speaking of enthusiasts, I have an inordinate fascination with screw threads which led me to respond a bit late to this thread (no pun intended).

David

[David LindquistParticipant @davidlindquist71920]

Posted by File Handle on 25/08/2023 18:22:58:

Posted by Nigel McBurney 1 on 25/08/2023 12:01:54:

I suspect that the odd size whit tap was used by some manufacturer who wanted to sell spares or service for their product and ensure their service was not easily copied by other suppliers or service providers.

I am not convinced that this was always the case. Stanley are often accused of this with the thread sizes on their planes, but they developed the design before thread sizes were standardised and never they changed them. It may or may not have been an advantage with sales, but not the primary reason.

A little bit of a story… Here at Knight Foundry and Machine Shop (Sutter Creek, California) we have a planer built by the G.A. Gray Company of Cincinnati Ohio circa late 1890's. The oil holes, of which there are many, have threaded brass plugs several of which had been replaced with wooden plugs. I got the job of making replacement brass plugs. Turned out the plugs are threaded 9/32-24. A google search for a die turned up among other sources a site that caters to collectors and restorers of Stanley planes. Turns out this thread is used on some of the bits on some Stanley planes. Got the die making, my job a lot easier than single pointing 6 to 8 of these. Got a tap too to clear out the threads where a wooden plug had been used.

David

[Michael GilliganParticipant @michaelgilligan61133]

As a ‘reference’ for your interesting tale … may I suggest this: **LINK**

https://tttg.org.au/Content/Docs/Articles/Stanley-Planes-and-Screw-Threads-Part-2.pdf

MichaelG.

[peak4Participant @peak4]

Posted by Michael Gilligan on 28/08/2023 07:53:39:

As a ‘reference’ for your interesting tale … may I suggest this: **LINK**

https://tttg.org.au/Content/Docs/Articles/Stanley-Planes-and-Screw-Threads-Part-2.pdf

MichaelG.

Here's a similar one for Singer Sewing Machine Threads
https://www.singersewinginfo.co.uk/screw_threads

Bill

[David LindquistParticipant @davidlindquist71920]

Posted by Michael Gilligan on 28/08/2023 07:53:39:

As a ‘reference’ for your interesting tale … may I suggest this: **LINK**

https://tttg.org.au/Content/Docs/Articles/Stanley-Planes-and-Screw-Threads-Part-2.pdf

MichaelG.

Thank you very much for this. A very rigorous and interesting piece going well beyond just the 9/32-24 screw. For example I had thought that the number size machine screw series in the US dated from 1907 but that was the year the ASME codified it basing it on an earlier number series going back to at least the mid-1890's. Lot's of good stuff here, including references. Found a copy of C.H. Saunders's 1894 book Hand Book of Practical Mechanics on ebay and ordered it. (Evidently it's not a "rare book"

David

Edited By David Lindquist on 28/08/2023 20:59:50

Edited By David Lindquist on 28/08/2023 21:01:06

Edited By David Lindquist on 28/08/2023 21:01:40

[SillyOldDufferModerator @sillyoldduffer]

Posted by David Lindquist on 27/08/2023 23:48:16:

Posted by File Handle on 25/08/2023 18:22:58:

Posted by Nigel McBurney 1 on 25/08/2023 12:01:54:

,,,

,,,

A little bit of a story… Here at Knight Foundry and Machine Shop (Sutter Creek, California)…

David

Sutter Creek, now that's an interesting historic location!

Is there still Gold in them thar hills? Hope so, I've swapped the wife for a shovel and am on my way!

Dave

[David LindquistParticipant @davidlindquist71920]

Posted by SillyOldDuffer on 28/08/2023 21:59:23:

Posted by David Lindquist on 27/08/2023 23:48:16:

Posted by File Handle on 25/08/2023 18:22:58:

Posted by Nigel McBurney 1 on 25/08/2023 12:01:54:

,,,

,,,

A little bit of a story… Here at Knight Foundry and Machine Shop (Sutter Creek, California)…

David

Sutter Creek, now that's an interesting historic location!

Is there still Gold in them thar hills? Hope so, I've swapped the wife for a shovel and am on my way!

Dave

There's still some gold but it will take a lot more than a shovel to get at it. When I docent at the foundry during tour days I like to tell people that that romantic image of the 49er with his gold pan didn't last very long. It soon took hard rock mining, digging waaay down in the earth, to extract a meaningful amount of gold. And this required an industrial base, foundries and machine shops, to support it. The first foundries came in in the early 1850's, Knight started in the early 1870's.

Even in the early days of the gold rush the real money wasn't in picking up gold nuggets from a stream bed, it was in, for example, selling shovels to those who hoped to do so. Google Sam Brannan, "California's first millionaire."

David

[Nigel McBurney 1Participant @nigelmcburney1]

Another company that used odd ball threads was the Douglas motor cycle company,on their early bikes they used pitches of 25 and 27 and diameters in sixty fourths. possible again to ensure customers had to buy spare nuts and bolts from Douglas.

[Nigel McBurney 1Participant @nigelmcburney1]

More on taps,a local tractor collector bought a bargain lot of unc/unf taps at a sale, then found the were problems they were well over size, he had bought Helicoil taps.

[Gep EnglerParticipant @gepengler40547]

Here, you can find a lot of information about threads; "normal" as well as many "exotic" threads.:**LINK**
Includinng several forms of WW.
This is by far the most extensive overview I have ever seen on Internet (In English as well as German language)

But unfortunately, I could not find the thread you are looking for, even there.

Best regards from The Netherlands, Gep

[File HandleParticipant @filehandle]

The only 0.2 thread I have found is Holtzapfels N which has a pitch of 36.1. From https://journeymans-workshop.uk/downloads.php link

[Author]

Posts