Does anyone know what thread size a tire valve stem and the Schrader valve are?

I've got an automatic chicken waterer (made by Little Giant) that uses what looks to be a truck valve stem and a common automotive Schrader
valve. It froze again and broke a fitting and I have tried to find a tap and die in the past that matched up to these threads, but no luck. I tried Google and am probably using the wrong key words, but no luck there either. Does anyone know what sizes these would be? Thank you.
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We went over this here a few years ago, so it should be archived on Google Groups. It's really odd and a couple of us did some digging to come up with it.
-- Ed Huntress
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Ed Huntress wrote:

I went through that a while ago. The external threaded part of a Schrader valve is 7.7 mm (.302") x 32 T.P.I.
YOu think my memory is that good. I found it on the site below.
http://www.sheldonbrown.com/gloss_sa-o.html
John
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First off, thank you for the information. I figured if I knew the size I could get the taps and dies, but they don't seem to exist. I've got the little 4 way tool with the thread chasers, but am really surprised that no one seems to make a tap and die set for these valves. McMaster-Carr doesn't have them and a google search doesn't pull up any, either.
I was able to make a replacement part from a piece of nylon and fudge the threads close enough that it seems to be working fine. But the lack of taps and dies is a surprise.
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wrote:

Any time I need these threads, I take a discarded valve stem from the tire shop garbage, cut the rubber off, wire brush it clean and silver solder it in place. I even have one of these complete with core and installation tool/valve cap in the glove box in case some a**hole pulls a core on my vehicle again. Gerry :-)} London, Canada
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I've fought this several times while making custom accessories. I forget precisely what thread it is, but IIRC, it's a 5/16"-34... a REALLY bastard form.
I finally took one of the better quality chasers and hardened it to use as a tap (in brass, only).
I called Schraeder valve, and they DO make the tap -- about $140, custom-run only.
LLoyd
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Don't have my books handy, but isn't it 1/16" straight pipe?
Dan
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That is 27 tpi. Another poster in this thread reports it to be 32 tpi.

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Wally writes:

Reputedly:
Internal thread 0.209 inches (5.3mm) by 36 threads per inch (0.706mm pitch), External thread is 0.302 inches (7.7mm) by 32 threads per inch (0.794mm pitch).
I haven't confirmed these.
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Richard J Kinch writes:

And I should add, that the reputed measurements aren't sufficient specifications for actually cutting these threads, if that's what you had in mind, although if you know thread-cutting, you can figure it out.
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On Sun, 18 Dec 2005 22:29:31 -0600, Richard J Kinch

That internal thread sounds awful close to 12-36. I bet a 12-36 tap would do the job.
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wrote:

The following link it's
7.7 mm OD 32 tpi, or 0.794 mm pitch Minor diameter is 6.9mm Thread designation is .305-32 or 7.7-32
http://www.engineersedge.com/wwwboard/posts/2386.html
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Most automotive stores sell a thread chaser for tire valves. It will fix the internal or external threads on a tire valve. I have several lying in my toolbox. Bugs
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Even out here in the outback they are around, so you should be able to find one, check with your local tyre store!
Should cost less than a six-pack!
Hope this helps, Pete

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replying to Wally, shotgun wrote: A standard Shrader Valve male thread is .305 x 32 T.P.I. Taps are available but very expensive!
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On Fri, 19 Aug 2016 18:18:02 +0000, shotgun

That's for the cap. <g> It's .210-36 NS internal. I stopped working on air conditioners way back, mid '80s, but they also have Schraders and are differently sized. There are many standards now.

Here, maybe. $25.10 for a North American Tool tap. http://tinyurl.com/h3zlc5v
But If you're just chasing threads, you can get a 4-way valve tool for $1.46 or four for $5.65 on Ebay. Tap, die, valve remover, and reamer. http://tinyurl.com/j6vsa58 or http://tinyurl.com/j94fodn
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On 8/20/2016 1:16 AM, Larry Jaques wrote:

What about "Judy Blow-up Dolls"?
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wrote:

None of my do...oops, nevermind.
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Tom Gardner wrote:

Isn't 'Fast Eddie' the only expert on those?
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On Sat, 20 Aug 2016 16:59:50 -0400, "Michael A. Terrell"

What's that supposed to mean, asshole?
--
Ed Huntress

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