Thanks for all the info to all who responded on this thread. I'm amazed at
how much all of you know. In fact I'm a bit embarrassed. I should have
known some of that history on the metric system. I just assumed that all of
Europe was metric all along including GB.
Wade Shanley
wadesh@msn.com
74 MGB
75 MGB
----------
From: Russ Wilson
Sent: Friday, November 08, 1996 3:39 PM
To: Wade Shanley
Subject: Re: Why standard?
Wade:
The American system of measurement comes from England (which is why our
units are often referred to as "English units"). The Brits only recently
adopted the metric system. In fact they started the conversion process
about the same time the US did, around the time MG production ceased, if I
recall. The only difference is that they stuck with it, whereas we
Americans gave up in the face of enormous public resistance. I just
finished some technical work with a collegue from Scotland who is in his
late 20's; he was as likely to refer to a dimension in inches as in
centimeters. However, the fact that we both use the same unit of
measurement doesn't mean that our nuts and bolts are necessarily
interchangable. That issue is an economic one.
There are very odd bolts on the T-series cars that combine metric threads
and English wrench diminsions (a "system" sometimes referred to as Lord
Nuffield's merry mixup), but this is an historical accident related to the
French company Hotchkis (sp?) building a metric screw plant in England
before WW2 to avoid the expected German occupation of France.
The Whitworth sizes that are being discussed in the group are an English
size, ie, based on inches, not cm, but are simply different from the
American NC and NF (or SAE) threads. Some Whitworth threads have the same
pitch as an SAE thread so the two can be screwed together but the threads
have slightly different cross-sectional shapes so shouldn't really be
mixed. Whitworth threads were gradually phased out after the War because
of the massive influence of the US economy. I believe the only Whitworth
threads that made it to the MGB were those that were incorporated into the
British standard pipe (BSP) system and used on things like radiator drain
taps and hydraulic fittings.
Russ Wilson
|