I would have thought that for tolerances, you would find the metric equivalent of the "gnats c*ck" rather more useful
Regards, Tony
I would have thought that for tolerances, you would find the metric equivalent of the "gnats c*ck" rather more useful
Regards, Tony
Gnat's c*ck flaccid, or gnat's c*ck rampant?
Regards,
David P.
Tony Jeffree wrote ...........
To which David Powell wrote in response .................
Could it be that 'rampant' and 'flaccid' are the top and bottom limits of the tolerance?
Mike
I thought something smelt a bit odd. ;)
Mike
Sounds like a pretty tight tolerance to me ;-)
Regards, Tony
In engineering/workshop practice, the metric unit used for these measurements is usually the "hundredth", or 1/100 of a mm = 10 microns. The 'thou' is equal to 2.54 "hundredth"'s.
I prefer the micron myself, 1/10th as big as the "hundredth" - a "thou" is equal to 25 microns.
"Within a few tenths (of a thou)" translates roughly as "within a hundredth", or "within 10 microns".
Thanks; a hundredth also seems like a useful unit!
Dave
Not quite. The preference for powers of 3 prefixes can be attributed to many organisations. But the SI authority
Normalised notation and engineering notation are well described at
Getting these wrong are sure fire ways to lose grades in your work at uni.
Centimeters are for dressmakers and BBC announcers and fall into the 'other' measurement units used by these morons. Like it's 3 football fields long, fine if you knew the British Standard for a football field. Looked on the back of my starret ruler and it had mm to in, litres to gallons but no football fields to shuttle launch vehicles.
Oh well another flat battery in the car park of life.......................
-- Regards,
John Stevenson Nottingham, England.
Visit the new Model Engineering adverts page at:-
But isn't there some vague conection between horse-drawn carts and roman roads to shuttle launch vehicles?
Peter
from John Stevenson
Unfortnate choice of reference there John.
There is no British (or any other) Standard for the size of a football field.
A month after buying my first house (1972) I had a note through the door telling me that the council were preparing to pull it down to re-develop the area and provide a football field for the local school. I won't bore you with the detail but I became chairman of the fighting committee and my research to find out how big a football field was brought zero results.
Even then ratio of length to width is not defined - though I think that the goal size might be!
JG
Hm quite right, I never knew that, have been labouring under a misapprehension. It is however a slightly odd prefix, in that although the centimetre is universally recognised, the centigram, for instance, is rarely used, as are other centi-units, and even the centimetre is frowned upon in official circles in the USA.
David
The US do use the centi-dollar quite a lot, though :))
Dave
Doesn't buy a lot though.
David
Neither does the Dollar, come to that.
Regards, Tony
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cht
An imperial inch is 25mm exactly.
A metric inch however, is only 25mm.
:-)
Hywel
2cd$4665ba20$d4bb5625$ snipped-for-privacy@news.chello.nl...
richt
My weak joke didn't come even out right...
Meant to say, imperial inch is 25.4, but the "new" metric inch is 25mm exactly.
Sorry, I'll get my coat.
I'll have to try this on the letters page of the Daily Mail saying it's the new Euro-inch. Bet they publish it.
Hywel
I think we should all change to the FFF system of units - see:
Regards, Tony
Reminds me of a collegue who, when asked "how long's a nanonsecond?" held his fingers about a foot apart, and said "about this long". Took me a good few seconds to realise he wasn't being silly: he was an electronic engineer. Even more valid now meter is officially defined in terms of time, rather than wavelengths of such-and-such.
Physicist define mass in terms of electron volts - and if I recall correctly that isn't just in terms of energy (E=mc2), but has an additional in-built fudge factor you're expected to know (mass of whatever particle I think) - though might be wrong on the last point.
Another confusing one I've heard of but not seen, is a tape measure graduate in feet and tenths. Catches out those of us expecting inches.
But then, tyre sizes are typically mm across and inches diameter.
And (British) BA screws are a metric thread, and (German) DIN diving valves are 5/8" (or something) BSP.
Hywel
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