"Dave Osborne" wrote in message
...
Hello Folks,

There was a discussion on here maybe earlier this year, maybe last year
about whether the thread on a tripod/camera was 1/4-20 Whitworth or UNC.
ISTR we got into discussions about thread angles and somebody pointed out
that Wikipedia was (allegedly) wrong.

Thing is, I can't remember who had the last word, and I can't find the
discussion on Google Groups.

Without wishing to open the debate again, did anyone find the definitive
answer, cos my colleagues and I were having fun recently with a load of
(supposed) Whitworth bolts/nuts and studding, some of which was compatible
and some of which wasn't!

1. Stud would screw into camera
2. Bolt would *not* screw into camera
3. Nut would screw onto *both* stud and bolt

Cheers,

Rumble
As I recall, it is Whitworth - the camera standard was set before UNC was
introduced in 1948.

UNC is a 60 degree form and Whitworth is 55 degree. Pitch is the same - 20
threads per inch. Obviously there are manufacturing tolerances which may
explain your experience.