MadModder

The Breakroom => The Water Cooler => Topic started by: jim on December 21, 2009, 01:07:56 PM

Title: tyre valve thread size
Post by: jim on December 21, 2009, 01:07:56 PM

i was just looking around the shed for some taps/dies. found some nuts off tyre valves (i always save them, never seam to need them!).

just wondering what thread they were :scratch:

found this http://www.gewinde-normen.de/en/valve-thread.html (http://www.gewinde-normen.de/en/valve-thread.html)

its a .305" 32tpi / 7,747 x .794 pitch thread.

unless i'm missing something, how on earth did we end up with a thread that is neither metric or a fractional imp size :scratch: :scratch:

and whilst i'm on the subject, its bothered me for a long time that tyres are both imperial (dia in inches) and metric (the width) ::) ::) ::)

i'm going to use the nuts on my poppin engine, just need to "pick up" the thread and open out a bit, it'll bother someone one day that i used M8 .8mm pitch threads :lol: :lol: :lol: :lol: :lol:

Title: Re: tyre valve thread size
Post by: Stilldrillin on December 21, 2009, 01:19:13 PM

Jim,

There are some things in this life, it is better not to know.....  :D

I once thought about those sizes, when I was an apprentice learning to measure things.  :wave:

I never did find out....... That was 50 yrs ago!  ::)

David D

Title: Re: tyre valve thread size
Post by: sbwhart on December 21, 2009, 01:42:29 PM

Jim

Thats near as dam it 3/16 * 32 Model Engineering thread you can get taps and dies from a number of suppliers try Tracey Tools.

Hope this helps

Srew

Title: Re: tyre valve thread size
Post by: mklotz on December 21, 2009, 02:06:28 PM

Quote

Thats near as dam it 3/16 * 32

Huh?  How's that?


3/16 = 0.1875 ~= 0.305  ?

Yep, true for small values of 0.3. :)


(or is this one of those weird British things like hundredweights that weigh 112 lbs?)

Title: Re: tyre valve thread size
Post by: tel on December 21, 2009, 02:39:27 PM

In my experience the threads on Schraeder valves are always 5/16" x 40 tpi - don't ask me why.

Title: Re: tyre valve thread size
Post by: sbwhart on December 21, 2009, 04:00:03 PM

 :doh:

Whoops I mean 5/16"

Some ones been swaping the little numbers around again.

Its been a long day

 :lol: :lol: :lol: :lol:


Stew

Title: Re: tyre valve thread size
Post by: Stilldrillin on December 22, 2009, 02:27:53 AM

I`m still confused......  :scratch:

Title: Re: tyre valve thread size
Post by: Bluechip on December 23, 2009, 07:09:31 AM

More confusion for you ... see 'Dunlop' threads ..

That German site has errors in it .. although not on tyre valve threads  it seems ..

http://www.watchman.dsl.pipex.com/thread.html

Dave BC