"JR North" wrote in message
.. .
My '70 Datsun Roadster has some bolts that are 6.5mmX28tpi. Took a
while to figure that one out.
JR
Dweller in the cellar

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?

Tyre Sizes are mostly given (cast into the rubber) With the wheel
diameter in inches and the tread width in millimetres.

John G.