In a message dated 98-01-03 18:04:23 EST, curry@wolfenet.com writes:
[in reply to John's e-mail:]
>> In Canada however, their are two systems:
>> metric and SAE.
>> I assume that the US is the same.
> John,I use good ole' USA standard "inch measurement" tools on my Spit
_______________________________________________________________
Joe et. al. Those "good ole' USA standard 'inch measurements" are the same as
those measurements called SAE (for the Society of Automotive Engineers). The
SAE is a U.S. (and maybe Brit/Canadian) organization which adopted those
measurements commonly in use at the time of the adoption. The standard for
length was yards and - from yards - feet and inches. In addition to the
standard for length, the SAE adopted standards for lubricants and other
automotive parts.
Yards, feet and inches were originally English Measurements. We use them in
the U.S. because we were British colonies. The U.S. first standardized ALL
U.S. measurements in 1830 and made some changes - that is why the U.S. gallon
is different from the Imperial (read Brit) gallon. But linear measurements
(feet, yards and miles) remained the same in the U.S. as in the U.K. from
colonial times to the 1970's when the UK mandated the metric system as the
standard.
Our TR's were built in the 1950's and 1960's using the English System of
Common Measurements. The standards for length are the same as the SAE
standard of measurements for length. U.S. car makers in the '50's and 60's
time frame used the same system of measurements. U.S. car makers are
currently moving toward the Metric system as a standard and have been for
about 20 years.
To add to the confusion regarding British built cars, the Whitworth standard
of measurement was another British system used by Brit car makers. This
system was originally designed for fasteners (screws and such). The Whitworth
system was in inches but used a different way of measuring bolt heads. This
system was in use in U.K. industry (not the U.S.) from the mid 1800's until
the mid or late 1940's. British auto makers used the British Standard
Whitworth during that period, which is why early Brit cars need "Whitworth"
wrenches. (Moss and others still sell them). By the time our Triumphs were
built the Whitworth system had been abandoned - 1944 actually. Some Brit auto
makers used the Witworth system into the 50's and maybe the '60's but Standard
Triumph did NOT use it for cars designed/made in the 50's and later. But that
is a whole other subject.
France developed and standardized on the Metric System during the Napoleonic
era (1801) and by 1900 the rest of continental Europe had followed suit. The
Brits remained on the "British System," that is yards, feet, and inches until
the 1970's when they finally mandated a move to the Metric system.
Interestingly enough, in 1893, the U.S. defined the yard based on a metric
equivalent! By the mid-20th Century the U.S. had recognized the metric system
for legal use in the U.S. but not as the standard for our measurements. U.S.
automakers started a transition to metric measurements during the late 1960's
in order to better compete in the world marketplace. That is why, as someone
on the list pointed out, some U.S. cars today have some metric components.
It appears to me that we unnecessarily complicate this whole subject as
regards our cars. When our TR's were being built, the U.S., and the U.K. and
its other/former colonies (Australia, Canada, NZ, S.A. etc.) were all using
the same system of measurements. That system is what we call Standard or
S.A.E. here in the U.S. It is what was used in building our Triumphs because
it is the same system which the Brits had invented and used for centuries and
what they went back to after abandoning the Whitworth system. As for Triumphs
built in the '70's (for example - the TR7's and 8's) - Since the U.K.
converted to metric in the 1970's and remembering that you can't convert
overnight because of the amount invested in existing machinery - I'll guess
that some fittings were metric on late Triumphs.
BTW - in the '60's I always had mechanics trying to use metric wrenches on my
TR4 because it was a "foreign car". In those days, as now, German, French,
Italian, Japanese (not very many around then), and Swedish cars were metric.
I found that the best thing for me to do was to assure the mechanic that the
Brits built their cars to our specs. This was not really true but it wasn't
false since the specs were the same.
As an aside - 95% of the world now uses the metric system but reactionaries
in the U.S. keep blocking our complete move to it. We spend years as kids
learning fractions just so we can deal with the "English System" which is
defined as the "United States Customary (from Custom house) System." The
Metric System requires no skill with fractions. IMO, it is pretty dumb to
have to constantly make calculations such as "what size wrench is between a
3/16th and a 5/16th" (it's a1/4 in) or that a 1/2" wrench is between a 7/16
and a 9/16. With the metric system all one needs to know is that 6mm comes
between 5mm and 7mm. If we in the U.S. mandated and moved to the metric
system it would take about 40 years (2 generations) to be completely rid of
the old inches/feet based system. The way we are now doing it now will take
about a hundred years or more.
But I digress. The answer to the original post is that when working on your
Triumph you will need tools called SAE or Standard if you live in the U.S. or
Canada. However, you might need some metric wrenches or sockets if your
Triumph was built during the '70's or if the DPO replaced nuts/bolts or parts
and incorrectly used metric replacements.
This is not the definitive story of these measurements. There have been books
written on this. I have merely tried to cut through a little of the
confusion. AND I await the inevitable corrections/expansions. Cheers.
Art Kelly
|