I had a '68 Triumph 500 TT... Half BA and half SAE... talk about a bitch to
work on... IIRC *most* of the serious engine parts were BA, for sure the
side case covers were 1/4-20 and a couple of other odd bolts were SAE...

--.- Dave



"Trevor Jones" wrote in message
news:QlaHi.51807$bO6.44944@edtnps89...
_ wrote:
On Sat, 15 Sep 2007 22:23:52 -0500, Richard J Kinch wrote:


There's an odd thread, called the Leica thread, that is used on
photographic enlarger lenses. It is specified as 39mm in nominal
diameter but 26 tpi in pitch.

I'm wondering what other monstrous metric-English combinations are out
there?


Campagnolo bicycle axles. 9 and 10mm x 26tpi.


IIRC the thread was Cycle Engineering Instutute (CEI)

Set the lathe for 26 tpi and make whatever you needed.

Not as bad as the BA series of threads, where the sizes and pitches are
nominally english, but based on metric measurments.

Cheers
Trevor Jones