Originally Posted by 3alarmer

No, the spindles are not all the same. There are charts in Sutherland's4th and 5th editions
that list this information in a handy format, which i cannot find to cut and paste right now.

ISO, French, Italian are all nominally 16mm in diameter, 15.9mm actual
English is smaller.....5/8 " diameter, 15.8mm actual

Sometimes you might be able to get away with a swap like this if you use
the correct crank to go with the same spindle.

By far the most vexing thing in swapping these is the various incompatibilities
between cups and spindles, and the different (and seemingly endless) positioning
of the cone shoulders and the flats, as well as the lengths and offsets.

If you can find a copy of Sutherland's to look at (4th, 5th editions) online or
at a bike shop, it explains a lot of this very nicely.

Or you can just measure and experiment. It's unlikely the swap you have in
mind will work, though anything is possible. You'd have to use your Raleigh
cups if they are Raleigh threaded, and the chances of the French spindle and
crank to fit it going in there properly are pretty slender.