I had long assumed that BA screws reigned supreme in the smaller sizes until I dug out my Meccano to do some prototyping.
Googling out of curiosity, I find that the Meccano screw thread is 5/32 Whitworth.
Some of my Meccano bits which ended up in the prototype are nickel-plated and therefore approaching their first century. (I'm not quite that old :-) , when I was given a No 3 set in the mid 60s, someone hearing of my interest donated to me the remnants of his grandfather's set)
We`re running 5,000 brass nuts this week.17/32" x 26tpi.Ok it`s BSB but still Whitworth form.Been running them regularly for years and unless the product sales dry up don`t see it stopping in the future.
Plenty of Whitworth bolts on cheap imported Chinese machines. Often with metric heads. 1/4BSW & 12mm AF is in regular use.
BSW has ideal pitches for threads in CI
Bob
And of course camera tripod fittings are (technically) 1/4" BSW, although a lot of manufacturers describe them as UNC.
...except for the ones that are 3/8" BSW of course :)
Regards, Tony
Yes - I'd (long!) forgotten about those...
They are enjoying a revival on higher spec tripods/ball heads etc these days...
Regards, Tony
I think the spec has actually changed to be UNC, but by convention/tradition the threads are cut with so much slack the UNC/BSW difference isn't really important.
BugBear
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