>
> I've always wondered why the "EN-40" cranks in Cooper-S engines, for
> example, use EN-40 steel, when no other reference on steel I've happened
> across talks about EN -anything! Anybody got the good word on EN-stuff vs
> 4340, etc?
> Brian Evans
As I Understand it
During WW II there was a need for a steel clasification system, so it was
decided to give the steels numbers, so everyone would know what was going
on. Being a time of crisis, these were termed an Emergency Number (EN)
EN1a was mild steel etc
Only trouble was, our system was liked by the bloody frenchies etc so with
everything else going metric the system was supposed to have been "thrown
out"/ disregarded from the mid 70s.
The only trouble is that engineers in the UK still use the system. Big
companies disaprove, so the engineers convert it to other systems. The
orders are received at suppliers who then convert it back. Still today if
I go in to our local steel store and ask for 127M326 (or what ever it is)
the guy behind the counter will look at me a bit puzzled, think for a
while and say "Oh you mean EN36T"
Geraint
PS I can find out the spec of EN40 later today
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