RE : More metric

[Simon Favre <simon@domain.elided>]

I think the counter person commenting on this wasn't complaining about hoses.
While it's true that specifying a hose by I.D. doesn't tell you what clamp
to use on it, most clamps are adjustable. The big difference in metric
hardware comes in the thread pitches and depths. In 8mm, you can pretty
much count on having either 1.0 or 1.25mm pitches, but in 10 and 12mm bolts
there could be one of 3 different pitches. Even having a bolt and nut of the
same pitch and diameter doesn't guarantee they will be a good fit due to the
shape and depth of the threads being cut. The other thing about metric 
hardware is that you see a wide variety of finish and hardness from one
country to another. The German and Italian cars have lots of hardened bolts
that are black in color. The Japanese tend to use softer steel and cad-plate 
everything. There can also be 2 different bolt head or nut sizes for the same 
bolt/nut diameter and pitch. On the Alfas, there are 8mm nuts that take a
13mm wrench, and some that take a 14mm wrench. At least in the SAE system,
things are pretty predictable. You have to ask for the "heavy" nut to get a
bigger one.

The first example of mixed hardware I encountered was a friend's Mustang II.
This was a P.O.S. car if ever there was one. It was also a maddening mix of
metric and inch hardware, mostly 5/16" and 8mm just waiting to be cross
threaded. The engine hardware was mostly American and the chassis was mostly
metric (Ghia body), if memory serves.