Metric or Decimal..accuracy?

Don't apologize, you answered the question and it's not really Gunner's fault that the three groups see so much of each other.

TK

Reply to
TDKozan
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I appreciate your 'zeal' but it seems you lost it a bit.

The distance between two stationary points is a constant, regardless of what unit of measure you use ????

A mile, there are different kinds, as opposed to a kilometer is a kilometer is .....

Reply to
Ace

Gunner,

You ask an interesting question.

Since we are all using machines with the same capabilities and likewise measuring tools, I would guess "more accurate" may have more to do with standards than anything else. For instance what is the British vs. American standard for bearing race tolerance, loose fit, tight fit, press fit parts? Same with but not limited to other standards bearings and threads etc.

Tom

Gunner wrote:

Reply to
brewertr

Once again: Time for truth, not rumor. Dispite the oft stated claim that only the US, Liberia and Myanmar (Burma to older readers) have not officially adopted the Metric System, the Metric System (later SI) has been the offical standard in the US for over an century.

History time:

1795 France adopts and make compulsory the use of the Metric System. A set of standard meter and kilogram prototypes are sent to the US, but the ship is lost at sea. 1812 France suspend the compulsory use. 1840 France reinstates the compulsory use. 1864 GB permits the use in contracts and scientific use, but forbids its use in retail sales. 1866 US permits the use in contracts and retail sales, and mandates that it is an acceptable system, forbiddinG any state from banninG its use. 1889 The US recieves a prototype meter and kilogram. 1893 By the Mendenhall Order, the US offically went on the metric system, with all measurements be defined in reference to the standard metric meter and kilogram held in Washington. D.C.. Any system could be used, but all measurements would be defined in metric terms. 1897 GB finally permitted the use of metric measurements in retail sales. 1958 A conference of English-speaking nations agreed to unify their standards of length and mass, and define them in terms of metric measures. The American yard was shortened and the imperial yard was lengthened as a result. 1965 GB decides to go metric "over the next 10 years".

Both the US and GB have used voluntary rather than compulsory adoption of the metric system. Both countries mandated that the system be taught in the schools in 1974. (Me? I was taught it in school in the US in

1964, but I went to a good school.)

1975 The Metric Conversion Act of 1975 (Public Law 94-168) passed by the US Congress. The Metric Act established the U.S. Metric Board to coordinate and plan the increasing use and voluntary conversion to the metric system.

1988 The metric system is designated the preferred system in the US. 1991 All US federal agencies and executive departments are mandated to use SI. 1994 All commercial consumer packaging in the US must use both SI and inch-pound labeling. 1995 GB mandates SI lableling on consumer goods, but permits dual labeling with inch-pound.

David J. Hughes

Reply to
David J. Hughes

No wind up intended. I use the term of art "US Decimal" to indicated decimal inch measurements, since the UK has gone to Metric.

Sorry for any confusion. None intended in this thread.

Gunner

"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."

- Onni 1:33

Reply to
Gunner

Bye dickweed

Gunner

"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."

- Onni 1:33

Reply to
Gunner

Thats sort of what I was thinking. THat and "rounding" of small decimal measurements either up or downwards

Gunner

"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."

- Onni 1:33

Reply to
Gunner

U.S. decimal system is based on the metric system in that there is no standard inch or foot. The definition of an inch is 2.54 cm. All length measurements are related to the meter which is defined as the length of the path traveled by light in vacuum during a time interval of

1/299792458 of a second. Accuracy does not depend on the units used in the measurement. You may be confusing accuracy with precision.
Reply to
J Gold

And, the British got it from the Romans. The "imperial" part of Imperial Measure refers to the Roman Empire, not the British!

Steve R.

Reply to
Steve R.

Thanks for posting this chart! I always woundered when the inch changed from 25.39997 mm to 25.4 mm

Nick

Reply to
Nick Müller

You missed the point.

If you want to know how big my horse is the "constant distance" is 15-2. You're kinda' screwed if you don't know "horse" measurements, aren't you?

The metric system has one unit for length, volume and weight and those units are related. The metric system is FAR superior.

Steve.

Reply to
SteveF

Do grow up, will ya? What did you expect? A big hug and a kiss on a cheek?

Reply to
zatoichi

Yes. The word is "preccision". By a definition, one unit system can not be more "accurate" then the other. Gunner should look up the dictionary entries for both of this words.

Reply to
zatoichi

"precision"

Reply to
zatoichi

The term is "United States Customary System"

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Learn it.

Reply to
zatoichi

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Reply to
zatoichi

Plonk

Reply to
StaticsJason

Precisely!

Reply to
iange

That would be the Imperial inch. The American inch was 25.40005 mm. The American yard was defined as 3600/3937 m by The Mendenhall Order 1893.

In 1959 it was changed again, to the exact value of .9144 mm. The conference David J. Hughes mentions must have been held the year before the actual legislation.

A little known fact (one of the very few things I have managed to remember from going to machinist's school for a short while a long time ago):

Long before the American inch was changed to the current standard of exactly 25.4 mm, the actual inch used in American industry was really the same as that, because the first set of measuring blocks delivered to Ford Industries (by the industry of my famous countryman C.E. Johansson) was made to that standard. This was probably due to someone making a mistake about the true size of an American inch. Ever since then, all measure blocks sold in America have been made to the modern standard of exactly 25.4 mm to an inch. When the mistake was discovered it was deemed unwise to suddenly change back to the real standard now that all the American industries were using the block standard.

I'm not sure about the British industrial inch of the time, but I guess they would get the same kind of measuring blocks as the Americans, only with the word "Imperial" stamped on the box. Anybody know for sure?

S.

Reply to
Sevenhundred Elves

I'm now looking in my (old) book of tolerance tables for Swedish standard. Most standard tolerances are given as whole numbers of micrometers, only the smallest of the basic sizes have tolerances given as tenths of that. Hope this helps.

S.

Reply to
Sevenhundred Elves

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