Threads ?! - and country isolation.

[graham-xrf]

Well - not all threads - just one thread in particular!
I happen to tangle with the fat T-nut stud that holds down the toolpost on my South Bend 9". The thread is a bit mangled right near the top. I guess a previous owner was careless with the lever nut. The hex nut under would not come off without some "persuasion". Just one of those little things we encounter all the time.

It measures 1/2", near exactly. I reach to the (few) dies I have. Hmm.. the 1/2" one is 20TPI - so that's UNF, and we are coarse thread - no good.
Rummage some more. There is a 1/2" 13TPI. That's UNC, and it won't fit! Just what is this?

Get out the thread gauges. It is exactly 12 TPI. Ah..Haa - so it must be a Whitworth!
Eh? Check threads carefully. 55° is definitely not it. Not Whitworth then. Check harder. 60° is definitely the thread cut!

I give up! This stud is a oddball one-off. 1/2" , 12 Turns per Inch, and has 60° threads.
I settle for a fine horology kite-section file. Maybe I will replace the whole shebang with M12.

Meantime, the farm neighbours behind have had the call to get shot full of vaccine. I anticipate my turn cannot be far behind. Yay! I so look forward to leaving behind a year that was so forgettable that I can't remember much of it, other than it slipped by while I hid out in the country like a hermit for 10 months. Just hanging in there hoping to make it to vaccine relative safety before the damn pestilence catches up to me. I know I don't much fancy my chances if it does before I get safe.

Why should I get to feeling so sorry for a silly chewed up thread? It's no big deal - right? Maybe I'm getting a little emotion affected symptoms. That's OK. I can read H.M. postings till the cows come home, fit a door frame, and fix up the mangled thread, and feel OK again!

 

[Lo-Fi]

Know just how you feel mate, think it's starting to bite us all. On the flip side, those of us fortunate enough to life out in the country seem to have a much better time than poor folks called out in small city flats. Finally looks like light at the end of the tunnel, rather than another government bungler with a torch. Spoken to loads round me who've had or been offered an upcoming slot for vaccine, all report well I'm pleased to say.

Could the thread have been single pointed at 12tpi with a 60 tool? We see all sorts on the steam locos... Metric hex bar stock to make a Whitworth fastener is a favourite.

 

[graham-xrf]

Know just how you feel mate, think it's starting to bite us all. On the flip side, those of us fortunate enough to life out in the country seem to have a much better time than poor folks called out in small city flats. Finally looks like light at the end of the tunnel, rather than another government bungler with a torch. Spoken to loads round me who've had or been offered an upcoming slot for vaccine, all report well I'm pleased to say.

Could the thread have been single pointed at 12tpi with a 60 tool? We see all sorts on the steam locos... Metric hex bar stock to make a Whitworth fastener is a favourite.

Thanks for the reply.
I am pretty sure I can find some 60° studding, but even if not, I can try my skills at having the machine make bits for itself. There is a nice poetic justice to that. This is the very same toolpost that pulls on the busted compound described in a thread from last October.



The toolpost T-Nut has to use the remaining "good" bit. Now, and after a bit of Brexit back-and-forth, my welder has arrived, and I am waiting for some e-Bay Nickel-Fe rods intended to weld up this sort of casting. For now, I am happy to just have the stud soldier on.

Re: Unreasonable odd feelings. OK - so we know some folks go a bit nuts. I never thought of myself as one of those. Definitely not going off in the "lose my temper" direction. More of a "sadness exasperation" thing at trivial small stuff nobody should ever get too wound up about. I'm pretty sure I will be just fine, but I am noticing it!

 

[Jim F]

1/2-12 used to be a fairly common thread in the US.

 

[C-Bag]

I ran into the 1/2-12 thing on the handles on my RF 30 of all places. I have 3 of them that I’ve repurposed for other tools. The quick release on my tail stock and the ball turner attachment I made. So it was worthwhile to track down and buy tap. I guess 1/2-12 is an old convention but why it would be on a Taiwanese machine from the late 80’s I have no clue.

my wife got vaxxed at work being med worker and has had no side effects. A fellow worker who got vaxxed at the same time got the spot she got the shot infected, go figgur. I‘m a hermit by nature and my work at home biz has not been impacted because it’s all on the net and through the mail.

 

[Jim F]

I ran into the 1/2-12 thing on the handles on my RF 30 of all places. I have 3 of them that I’ve repurposed for other tools. The quick release on my tail stock and the ball turner attachment I made. So it was worthwhile to track down and buy tap. I guess 1/2-12 is an old convention but why it would be on a Taiwanese machine from the late 80’s I have no clue.

my wife got vaxxed at work being med worker and has had no side effects. A fellow worker who got vaxxed at the same time got the spot she got the shot infected, go figgur. I‘m a hermit by nature and my work at home biz has not been impacted because it’s all on the net and through the mail.

I heard some where that 13 is not a good thing in Asia,so they still use 12.

 

[graham-xrf]

I heard some where that 13 is not a good thing in Asia,so they still use 12.

Good Lord! They are superstitious? !!
Next we gonna hear about Japanese machine tool design Feng Shui!

 

[RJSakowski]

1/2" 12 tpi with 60º threads dies do exist.

TTC 17-032-123 1/2

Special Thread Sized Adjustable Round Dies for External Threading Applications. TTC presents large assortments of over 300 round threading dies for cutting standard external right-hand screw threads. These external threading dies are made from high-speed steel and bright finished for...

www.travers.com

 

[jcp]

Somewhere in my dim memory of decades ago it seems as though someone told me that 12tpi was coarse thread for 1/2" in the late 1800's and very early 20th century. Sometime around WWII it was changed to 13 in the "new" standards. I have encountered 1/2-12 in some old oil field and agricultural equipment.

 

[silence dogood]

A couple of years ago I bought a Greenfield Little Giant tap and die set with it's original wood case. Beautiful, it was hardly used. All taps and dies are standard SAE except the 1/2" 12tpi. Funny thing, it turns out there was a project that needed a 1/2 12tpi. Try looking on ebay. Complete sets are not cheap (I was lucky, got mine for 75$, not ebay). Incomplete sets sometimes can go pretty cheap.