Dave Plowman (News) wrote:
In article ,
Frank Erskine wrote:

I'm trying to find out whether the ¼" bush for a camera tripod is a
Whitworth or a UNC thread - both are 20 tpi, but of course the thread
form is different.
Any ideas please?


It's Whitworth. Dates back to before Unified.


But UNC works for most jobs and is much easier to get hold of.

--
Spamtrap in use
To email replace 127.0.0.1 with blueyonder dot co dot uk