You know, my eyes aren't what they used to be. I'm now wondering if
this could be an 11-1 metric thread, which would of course equate to 25.4
tpi. Maybe 26 was just a hair too fine too, and I got it wrong. - GWE

Kelley Mascher wrote:

The closest I can find is British Standard Brass thread. They are all
26 tpi and while Machinery's Handbook doesn't list 7/16 specificly I
imagine it would be allowed since it's for brass tube and general
brass work. It is a Whitworth form.

So far I haven't been able to find an 11mm 0.95 pitch thread which
IIRC was another possibility.

Cheers,

Kelley

On Sun, 01 May 2005 08:46:22 -0700, Grant Erwin
wrote:


Harold and Susan Vordos wrote:

"Grant Erwin" wrote in message
...


A guy has this small hand torch with thread-on tips. He wants to make up
an adapter for different tips and as such he plans to start by making a
part that threads onto his torch. However, the thread is really unusual.
He asked for my help today and I looked at it semi-closely. Neither my
26tpi gage nor my 27tpi gage appeared to really fit it. It looked to me
like it was in between, call it a "26½tpi" thread. I miked the OD of the
threads and got 0.429" which isn't very close to anything except maybe

11mm.


The fit between the torch body and tips is a good fit, i.e. the thread

isn't

sloppy or anything -- if it were, it would leak -- and the threads are not
tapered. Under 10X magnification the thread form appeared a bit rounded.

Can anyone ID this thread? It is probably something to do with tube or
straight pipe thread.

GWE


Sounds like the torch was made in the UK. Is the form 55 degrees?

Harold


You know, I didn't look at it. I didn't have it in my hands very long, nor
is it here now. The torch is a "hi-heat" torch carried by several jeweler
supply stores e.g.:
http://www.kingsleynorth.com/skshop/....php?catID=218

It is marked "Made In China" but was said to have been designed in the US.
I'm sure about the country of manufacture but only have one unconfirmed
source on the country of design.

My little optical comparator was having some problems and is just a toy
anyway compared to a real one, so I couldn't ID the thread profile. When
I said the threads appeared rounded it was just a vague impression. I'm
hoping someone can recognize the thread by its OD (0.429") and approximate
thread count (26 - 27 tpi) and general description (straight tubing thread).

It occurred to me that this could be some form of 7/16" thread too as
0.429" isn't that much smaller than 0.4375", just .009", so this *could*
be 7/16-26½" thread, sigh.

GWE