An anonymous Yahoovian said:Quoted message said:I need a new seatpost clamp bolt for my 1970's Raleigh Team 753. The
seapost
clamp uses a Whitworth threaded bolt, correct? No common bicycle related
bolt I have fits.
A fellow Yahoovian using the alias 'Zog the Undeniable said:I got a piece of 1/4" Whitworth threaded rod from a fastenings supplier
last year.
If memory serves, the Yahoovian who goes by "Zog" is U.K. based, and it
wouldn't surprise me if such a thing were to be available in That
Sceptred Isle.
However, I also surmise that the O.P. is _not_ from the U.K. (if he or
she was, it's unlikely that the dififculty would have arisen.)
Quoted message said:Whitworth is still used for some applications,
This might be true, for all I know.
Quoted message said:camera tripod fixings in that particular size.
That's not correct. Camera tripods use S.A.E. threads. In the U.S.,
they use the ubiquitous 1/4-20 size. In much of Europe they use the
3/16-20 size.
Quoted message said:Incidentally, it was the first standard thread - fixings before
Whitworth were made so that nuts would only fit onto bolts supplied at
the same time.
That's correct. See the Whitworth entry in my Bicycle Glossary for more
on Sir Joseph Whitworth, one of the great tech guys of the 19th century.
Quoted message said:If memory serves the thread angle is 60 deg.
Nope, 55 degrees. S.A.E. and standard Metric are 60 degrees.
Italian bicycle threading is also 55 degrees, being a sort of hybrid
between Whitworth and metric (Metric diameters, Whitworth thread pitch
and angle.)
Sheldon "Not To Be Confused Witn Isambard Kingdom Brunel" Brown
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