Remember that lots of things don't follow the standards or follow conventions instead and not every company just instantly switched over because ISO decided to publish a standards document. I'm sure there is lots of whitworth stuff out there, possibly to this day, I don't know. My own tripods and monopod are clearly UNC.
Not the same as Whitworth, tripod threads are 1/4 - 20 NC (American National Standard - Coarse). The diameter and number of threads per inch are the same as Whitworth, but the thread form is different. From experience, all of us who owned pre-metric British cars in US know that an American fastener can be mated with a Whitworth one only once. It goes on, but will never come off, due to an interference fit.
That is correct. Many fennels are 1/4-20 UNC.
The ANSI Unified thread wasn't a standard until 1949. Lots of cameras before then had 1/4" tripod bushes so they must've been BSW...
Don't let facts get in the way of a good pedantic argument Frank. As I said earlier I have lots of camera-related items that demonstrably have BSW threads, others that have UNC, and I've yet to have any problems of any sort interchanging the two.
This application is hardly heavy engineering, the thead differences are completely insignificant for photographic purposes.
They both have the same pitch its just a minor difference in the shape of the thread. I think UNC bolts fit into BSW holes OK but I am not so sure the reverse is true. As the cameras are BSW it works fine.
As you say you aren't going to over tighten a 1/4" bolt using you fingers so its pretty much academic for a tripod on a normal camera. (That's not to say you can't damage a plastic tripod bush or even a metal one by putting in a bolt that too long.)
It is true.
I very much doubt that. Old cameras certainly are if they were made before UNC existed, but I'd be surprised if modern ones are BSW. Surely the camera thread and tripod thread are intended to be the same?
Exactly my point.
Of course length matters, but that's another topic altogether :-)
Unified is based on American threads - so UNC basically American Coarse. Although there are differences explained earlier.
But why do you think older camera accessories would use a UK thread? The UK wasn't the major maker of cameras, etc.
Because your assumtion is wrong, leading to:
Notes: [1] First proposed as a standard by Joseph Whitworth in
1841. [2] Example: P. Meagher, London had 3/8W tripod mounts on their "Tailboard" cameras certainly by 1874, perhaps earlier.Have something to add? Share your thoughts — no account required.
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