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  3. [SOLVED] Does anyone know what thread size a tire valve stem and the Schrader valve are?

[SOLVED] 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.
Reply to
Wally
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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
Reply to
Ed Huntress
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.
Reply to
Richard J Kinch
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.
Reply to
Richard J Kinch
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.
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John
Reply to
John
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
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Reply to
reply
That internal thread sounds awful close to 12-36. I bet a 12-36 tap would do the job.
Reply to
Don Foreman
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
Reply to
Bugs
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
Reply to
Bushy Pete
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.
Reply to
Wally
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
Reply to
Gerald Miller
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
Reply to
Lloyd E. Sponenburgh
Don't have my books handy, but isn't it 1/16" straight pipe?
Dan
Reply to
Dan_Thomas_nospam
That is 27 tpi. Another poster in this thread reports it to be 32 tpi.
Reply to
Tom Haughton
A standard Shrader Valve male thread is .305 x 32 T.P.I. Taps are available but very expensive!
Reply to
shotgun
That's for the cap. 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.
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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.
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or
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Reply to
Larry Jaques
What about "Judy Blow-up Dolls"?
Reply to
Tom Gardner
None of my do...oops, nevermind.
Reply to
Larry Jaques
Isn't 'Fast Eddie' the only expert on those?
Reply to
Michael A. Terrell
What's that supposed to mean, asshole?
Reply to
Ed Huntress

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