ArthurK101 skrev:
> > But I do recommend the SI system of measurements!!!
> Odd, by SI - I take it you mean the the Standard International
> which is metric?
> Art Kelly
Hi Art,
it says in my book;
" SI =Système International d'Unités =International agreement
on standardized measurements. Adopted by most countries and
suitable for all technical and scientific areas. "
and as You know it's virtually only the US that still haven't
jumped on this very effective train...
The SI handles all sorts of units and measurements like length,
mass, time, temp etc. The units have often been named after great
scientists of the past like; Newton, Hertz, Pascal, Joule, Watt,
Ampere, Kelvin, Farad[ay], Volt[a], Ohm, Siemens, Weber, Tesla,
Henry and Lumen to name but a few...
The metric threads are only just an offspring of the unit for
length which is m, for meter. It uses the [in this application]
more suitable fraction of the meter, the mm [millimeter, 1/1000
of a meter] to designate a certain thread.
- Like that darn French bastard the M7 which is 7 mm in outer
diameter of the thread. This thread have an inclination [pitch
in English?] of 1 mm per thread turn. It is listed in the least
favourable class of threads [Class 3] in the standard, together
with most of the other odd numbered sizes.
There are lots of metric threads, both coarse and fine for each
size, standardized between the diameters of 1 to 300 mm. The M300
for instance have an inclination of 6 mm per turn. The M300 fine
have an inclination of 4 mm and it's designated M300x4.
The metric thread standard allows [of course!] for larger sizes
but they are not normally published in the book.
BFN
Yours
/Odd
--
Odd Hedberg
Pomonagatan 4
S-74236 Östhammar International liaison secretary,
Sweden Triumph Club of Sweden
'70 Spitfire Mk3 FD82497LO Signal Red
E-mail: odd@triumphclub.se / odd.hedberg@bigfoot.com
Club URL: http://www2.passagen.se/triumph/
Home Telephone: Int+ 46-1731 7131
Geographical Position: N 60deg15min E 18deg23min
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