Ok guys, Im laying out the challenge...can anyone identify the thread used for tyre valve stem caps??!!
 
Im using a truck remote access extension to pressurise my Accusump and need a thin/half nut to secure the valve stem in the wheel arch access panel.
 
So far I can confirm the diameter is approx 8mm or 5/16"
 
The thread is finer than 5/16"unf and 8x1mm metric fine.
 
Anyone have any ideas what it actually is?
 
I have a feeling it will be a unique thread like the male thread on the tips of spark plugs...it doesnt match anything known to man!!
 
Cheers,
 
Phil.

It is known to man, but you'll have to machine up a nut I'd say
 
5/16" SAE FINE (5/16" dia. - 32 TPI)
 
Cheers
 
 

Who'd a thunk it, but there is more than one size of Schrader valve out there too:
 
http://en.wikipedia.org/w...rader_valve#Dimensions