5/16-26TPI Thread form?

Hello All,
Can anyone enlighten a poor yank about threads in the size of 5/16-26 TPI? This is called out for the piston gland nut on the Stuart Turner
model 10V casting set I am currently working on.
I have been trying to locate a tap and die for this size and have looked within the BSW, BSF, and BA series of thread forms to no avail. Of course they are also not to be found in the american system UNC or UNF types here. I have found most every other TPI but 26.
I suppose I can always substitute the UNF 5/16-24 size, but I have been faithful in all other instructions for size of threads and such with this engine.
This is one of two Stuart casting sets I inherited from my Dad, the other being a model 10H. The 10H had been started by him back in about 1970, but is only about 1/3 complete. The 10V was still untouched in its original box. I know they are quite old sets now. The price listed on the included instructions for an unmachined set was 1 + 3/4 Purchase Tax. They cost a lot more now I see. I really do not want to mess these up.
My grand plan is to finish them both as a matched set. So far so good, but I'm not that far into it at all. Mostly focused now on planning, research, and gathering tools, and as I said, I still need to get one more tap & die, 5/16-26. Any hints, or other help at all, would be most welcome at this point. I know my questions must sound like I'm a real newbie, sorry bout that. I suppose most of you guys built your first Stuart Double Ten at age 5, hooked it up to your Mum's tea kettle, and hob-nailed it into a home-built cedar-strip launch for lazy summer cruises on the channel. ;-). Do be gentle.
With kindest regards, Paul Schiller
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Look for BSB (British Standard Brass) or BSC (British Standard Cycle).Should get you what you need. Here`s a link to a page which has all the thread data. http://mdmetric.com/thddata.htm
Mark.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thread angle for BSCycle thread is 60deg. Whilst Thread angle for BSBrass is 55deg.
wrote:

Look for BSB (British Standard Brass) or BSC (British Standard Cycle).Should get you what you need. Here`s a link to a page which has all the thread data. http://mdmetric.com/thddata.htm
Mark.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article
snipped-for-privacy@ems-fife.co.uk writes

...and here is where you can buy them; the set is very good value, but if you just want the 5/16 size it is available on one of the other pages:
http://www.tracytools.com/variousalwaysin.htm
David
--
David Littlewood

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hi David, Remember the poor fellow is on the left bank of the pond. ;) Ned Ludd
David Littlewood Wrote:

--
ned ludd
------------------------------------------------------------------------
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Mail order works quite well for us buying from the USA; I have every confidence it works the other way too. Could be his easiest remedy, chance of finding BSB threading gear in the US is slim.
David
--
David Littlewood

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
PaulS Wrote:

Hi Paul, You are to be congratulated on your desire to use proper threads not that upstart yank stuff. There generally are two 5/16x26 TPI hreads BSB and BSCy/cei..Bsb stands for British Standard Brass, BSCy is British standard Cycle and CEI which Cycle Engineers Institution.. In 5/16x26 the only difference is the thread angle, BSB is 55 and BSCy is 60, just like your UNF/UNC. You should be able to get taps and dies once you know what to ask for, failing that try and borrow from a Britiron repair shop, or perhaps a push bike shop, but unlikely. Ned Ludd PS either BSB or BSCy should do the job, I dont think it is specified which to use.
--
ned ludd
------------------------------------------------------------------------
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Wow this news group now answers questions before they have been asked, just been out in the garage overhauling an old Record no 36 bench vice and was unable to identify the 5/16 x 26 thread which holds the jaws in place as one of the screws is snapped of flush and will need drilling out and possibly re-tapping. Was going to post on here see if anyone could identify the thread but no need to now, so thanks guys.
So next question, anyone know where a can get a pair of jaws for a record no 36 vice at a realistic price, the best so far is about 40 a pair which seems a bit steep for a pair of plates with two holes in and a knurl effect on one face, sizes are 6" x 1" x 1/2" & 4" ctrs.
Cheers Paul
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

I would guess most of us would just make a pair of smooth jaws (much better for most things as the serrations do damage work) unless you are mostly doing agricultural type stuff. Would cost next to nothing, apart from 1/2 hour of your time. Been meaning to replace the jaws on my 4" Record vice for some time for that reason, but I mostly use fibre slip-on jaws instead.
David
--
David Littlewood

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
So next question, anyone know where a can get a pair of jaws for a record no 36 vice at a realistic price, the best so far is about 40 a pair which seems a bit steep for a pair of plates with two holes in and a knurl effect on one face, sizes are 6" x 1" x 1/2" & 4" ctrs.
Cheers Paul
--------------------------------------------------------------------------- I need to avoid marking any work in my vice so the first thing I did was throw away the steel jaw faces and fit two smooth brass blocks in their place. Why not do the same, or are serrated steel jaws essential?
Cliff Coggin
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thank you gents one and all.
I'm off to search for BSB or BSC form 5/16-26 tap and die. No, Mr. Turner did not say which specifically.
One would think, this being a brass gland nut, that the BSB form is the natural choice if both are equally available.
The die is not really a big issue, as my lathe will cut a 26 lead, and either the 55 or 60 degree form tool is easy enough.
A tap however in my view is required as it is a short, blind hole in the CI boss. Not something I'd care to try to single point. I suppose in a pinch, I could try my hand at making a tap for this one hole. I've read how a dozen times, just not had an opportunity to try it myself.
Now, about which shade of green to use....? The instructions do actually suggest that green paint sets off the bright work well.
Cheers, Paul Schiller
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

A dark green is the normal choice - something like British racing green from the motor racing days of 50 years ago. Mid shades of green do look pretty frightful.
I also quite like a dark maroon shade.
David
--
David Littlewood

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:
(snip)

Paul
Stuart's are still trading, but without 'Turner' any longer. Their web-site is here http://www.stuartmodels.com They still distribute their own shade of dark green paint. Stuart part number 32-50-72388 consists of a small tin of black and a small tin of 'Stuart green' paint, both gloss finish. I have just spoken to Stuarts and they tell me the cost of the paint set is currently 6.75, plus 7.50 for P&P to the USA - approximately $22US.     
I have used this paint and would describe it as 'Brunswick green' if that means anything to you. Have a look here, one of the UK's biggest paint manufacturers: http://www.dulux.co.uk/servlet/ColourSchemeHandler?name=dp_brunswick_green
    I don't know if your US model shops stock 'Humbrol' brand paints, which are widely used for model application in the UK. It's my guess that Stuarts repackage the Humbrol Brunswick green under their own label. A small tin of Humbrol Brunswick green costs approximately $2.00. If pushed, I could possibly identify an international standard number which you could use in the US to match it locally, if $22 is too rich for you.
Let us know if you need any more help. --
Chris Edwards (in deepest Dorset) "....there *must* be an easier way!"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Paul
    Further to my earlier reply to your message, there's a US Federal Standard Colour Site at http://www.colorserver.net /.           Have a look at colour #34066 - my choice of a match for 'Stuart green'
--
Chris Edwards (in deepest Dorset) "....there *must* be an easier way!"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Chris Edwards wrote:

Unless you have good reason to do so, DO NOT trust colours on your browser, or (normally) your computer.
BugBear (with experience in colour editing and prepress)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Dear Chris, David, bugbear, and all others who so kindly replied,
Well I think I've found the perfect colour (note to self: not "color") then. Thank you!
You'll only have yourselves to blame for encouraging me when (not if) I become a pest around here. It's like feeding a stray cat.
-- Paul Schiller
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
PaulS Wrote:

We will leave out a tin of Kit e Kat for you, for the next time. And thank you for using English, English :) Ned Ludd
--
ned ludd
------------------------------------------------------------------------
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You will find that all the UK model engineering suppliers list the 5/16 x 26 thread as an *ME thread* not Brass or Cycle etc as everyone else has suggested.
Stuarts tend to use slightly less common threads on their glands and pipe fittings, most other makers would go for a finer ME thread such as 32 or even 40tpi, again easily available in 5/16 from the usual ME suppliers. Intersetingly Stuarts sell the taps as BS taps.
And you can get the taps & Dies from US Stuart Dealers such as Morris Miniatures
http://secure.enginemodels.com/cgi-bin/store/perlshop.cgi?action=enter&thispage=tools1.shtml&order_id =!ORDERID!
Jason
--
jasonballamy
------------------------------------------------------------------------
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Thank you for the very helpful link Jason. Yes, I understand what you're saying about the ME pitches. If I recall correctly, Guy Lautard of TMBR, lists 5/16-32 as the ME pitch for this size.
Best regards, -- Paul Schiller PDA Panache Corp.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

A note for our friends over the pond. ME threads use a Whitworth form i.e. 55 degree.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.