replying to melkie.au, fyiman wrote:
I don't have an R134a fitting handy so I can't check it, but ...

The "normal" thread pitch for a standard 1/4" bolt is 20 threads per inch
(TPI).
The "normal" thread pitch for a */fine/* 1/4" bolt is 28 TPI, not 24.

So, if it was a fine-thread 1/4" bolt, it's 28 TPI. Otherwise, if not, perhaps
you could check it with a thread guage.



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