Trying out metric

[rake60]

Prints may be drawn with metric, imperial, or some measurement based on the
width of the current King of Mars thumbnail or how far a common garden slug
can travel in 15 seconds. It doesn't change a thing when it comes time to
cut the metal. In any language a size is a size. You will either hit the size
or miss it. If you miss it make the mating piece to fit. It really doesn't matter
what the numbers on the paper are. They might me millimeters, they might be
1/16ths of an inch. If it fits together in the end and works, it is a successful
machining operation.

If you will excuse me now I need to go and recalibrate my adjustable Crescent
Wrench. It is Imperial of course and I need it to work on my Suzuki Tracker
tomorrow. Converting it to metric may keep me up all night!

Rick

 

[Davo J]

An easy way to get used to metric coming from imperial is to buy a metric/imperial tape, then you can easily convert from one to the other untill you get used to it.
Dave

 

[ToniTD1490]

From http://www.kanabco.com/vms/library.html

“There are two systems of measurement used in machine shops today, the Metric system and the Inch system.
The Metric system is based on the meter as the standard unit of reference. A meter (approximately 39.37 inches in length) is subdivided into 10 equal parts called decimeters. Each decimeter is divided into 10 parts called centimeters and each centimeter is divided into 10 parts called millimeters.
The Metric system is a very coherent system because it is exclusively a decimal system and therefore has a common multiplier and divisor of 10. Regular fractions are not used in the metric system. Instead the metric system uses only decimal fractions. Other names for the Metric system include SI units and ISO units. The Metric system is the most commonly used system of measurement in the world.
The Inch system is based on the foot as the standard unit of reference. A foot is divided into 12 equal parts called inches. Each inch is subdivided into a variety of fractions and decimals.
The Inch System is a rather incoherent system because it lacks the decimal based advantage of the Metric System. Parts of a foot can not be easily expressed as decimal inches. For example, in the metric system 7 millimeters is 0.7 centimeters which is 0.07 decimeters which is 0.007 meters. But 7 inches is 0.583333 feet which is 0.19444 yards and so on. This is a clear advantage for the metric system.
Another name for the Inch System is the English System. The Inch System is used in most English speaking countries but is being slowly replaced by the metric system.” I like Metric, because I learnt with the Metric System, but other people like Imperial.

Regards,
ToniTD1490

 

[tel]

The beauty of the metric system is that it's just so darned logical (to paraphrase Samuel Clemens, speaking of the Ethan Allen pepperbox) one litre, is defined as a cube 100mm on all sides, and, by co-incidence, weights 1 kilogram

 

[ToniTD1490]

In 1901 liter was described as the volume occupied by a mass of 1 kg of pure water in its maximum density and to normal pressure (to 4 °C and 1 atm respectively). This definition was repealed in 1964 because the liter was differing from the cubic decimeter in approximately 28 parts for million, inducing to mistake in the measurements that need enough precision. Nowadays only It is used as a special name of the cubic decimeter.

 

[tel]

Hmm .... it's close enough for me, at any rate.

 

[Maryak]

Do you still use that hundredweight (cwt) that weighs 112 pounds?

LENGTH

4 inches = 1 hand
12 inches = 1 foot
3 ft = 1 yard
5.5 yds = 1 rod pole or perch
4 poles = 1 chain
100 links = 1 chain
10 chains = 1 furlong
8 furlongs = 1 mile

WEIGHT

16 drams = 1 oz
16 ozs = 1 lb
14 lb = 1 stone
28 lbs = 1 qtr
4 qtrs = 1 cwt
20 cwt = 1 ton (long)

VOLUME

4 gills = 1 pint
2 pints = 1 quart
4 quarts = 1 gall (imp)
2 galls = 1 peck
4 pecks = 1 bushel
8 bushels = 1 qtr

These and many other wonderous ways of measuring things are all part of the rich tapestry of British ancestry.

Best Regards
Bob

 

[tel]

Yep, what's difficult about that? But you left out Rods and Perchs and other associated seafood Bob!

 

[Maryak]

Yep, what's difficult about that? But you left out Rods and Perchs and other associated seafood Bob!

The pole = the rod, both of which equal a perch, (if your very patient and very lucky whilst dangling your rod or pole in the canal with a maggot and a bent pin on a piece of string).

Best Regards
Bob

 

[mu38&Bg#]

If you will excuse me now I need to go and recalibrate my adjustable Crescent
Wrench. It is Imperial of course and I need it to work on my Suzuki Tracker
tomorrow. Converting it to metric may keep me up all night!

Rick

You must have an old one. That standard went out a while ago. My craftsman adjustable wrench is both metric and imperial. I'm not kidding.

 

[GWRdriver]

With exception of repair of foreign-built models most of my work is in Imperial but I've learned to flit easily back and forth between the two systems by choosing to memorize .03937 and using that in transposing dimensions. That is also an exact number, derived from the inverse of 25.4. Most people seem to prefer the 25.4, and that's their choice, but for me the .03937 prooved to be more convenient and more intuitive. Either way, as someone said, it's simply a way to measure distance between two points. One thing that helped me get a better feel for length in metric was to buy a 12" (oops! 300mm) scale and keep it lying around on the on the bench for an occasional comparative measurement.

 

[shred]

Ah, it must be time for the annual Metric-Imperial fest again

The only thing I dislike about metric, well SI, to be pedantic, besides not being able to get stock or cutters or much of anything else easily in it here, is they didn't do a lot of human factors work before deciding on the core units. Yeah, they're fractions or multiples of some universal constant (or are now), but there's a reason inches, feet, pounds and so on evolved over time to be the way they are (and pecks and ells and hogsheads fell by the wayside)-- in the core "units", they're a convenient physical size for the task at hand.

 

[mklotz]

Excellent point, Shred.

One of the best examples of this is the Pascal, one Newton per square meter. It equates to 0.000145 psi, way too small to be useful.

However, as always, people will rearrange the system to their own comfort. Now widely used, though not, I believe, endorsed by SI is the 'bar' or 10^5 Pascal, which is a useful size and, coincidentally, almost equivalent to one atmosphere.

Most of these derived units are, however, simply related to the primary units so conversion simplicity is retained - unlike the Imperial system where they would have probably defined it as 5280 Pascal or somesuch nonsense.

I don't why the SI attempts to suppress the intermediate units (e.g., cm, dm, cc, cg). There doesn't seem to me to be any advantage and much disadvantage. Include them and exercise control over the inevitable derived units to keep the system usable.

 

[Maryak]

I don't why the SI attempts to suppress the intermediate units (e.g., cm, dm, cc, cg). There doesn't seem to me to be any advantage and much disadvantage. Include them and exercise control over the inevitable derived units to keep the system usable.

Don't worry Marv,

I have a metric wife from a metric country and to measure anything cm is the only one used, e.g. 23 1/2 cm. I reckon it will never be suppressed as half the population refer to their dress, bust, waist, hip measurements etc. in cm.

We should be buying Newtons of potatoes but we buy by the kg; so if the boffins don't want their system misunderstood they need to go with the flow and as you say not impose unrealistic and sometimes meaningless terms/rules on an already confused transitional generation.

Best Regards
Bob

 

[mklotz]

Speaking of centimeters and the ladies...

The medical community still measures dilation of the birth canal in centimeters. Also, most syringes are calibrated in cubic centimeters.

Yes, Newtons of potatoes. At least the French had the good sense to not use the same unit name for force and mass.

Whenever I'm forced to deal with the Imperial system, I wonder, "Could they have possibly made it any worse?" I suppose the answer is yes, but I'm hard-pressed to understand how.

The astounding thing about the Imperial system is that its staunchest advocates don't understand it either. That explains why the USA will never adopt metric. If they did, they would have two measurement systems they don't understand.

 

[Noitoen]

mm or cm here in Portugal, depends on the profession. Carpenters use cm, machinists use mm and when they talk "precision" they use 1/100th of a millimetre.

 

[Loose nut]

The astounding thing about the Imperial system is that its staunchest advocates don't understand it either. That explains why the USA will never adopt metric.

Americans will not adopt the metric system because they don't want to, not because it might be a better system or it would put the whole world under a unified measurement system. The more they think that metric is being forced on them the more they resist, generally if they didn't invent it they don't want it. To some of them accepting the Metric system is tantamount to announcing the arrival of the anti-Christ.

As for making the whole world unified under one measurement system, why should we, nothing else in the world is unified, different language, religion, money, government types, calendars, standards for the same things, etc, etc, etc.

The only way we can get the whole word onto one system is to throw out both the imperial and metric system and institute a new universal system that everyone will use, then we will all be the same, miserably unified.

 

[zeeprogrammer]

then we will all be the same, miserably unified.

Rof} Rof}

I love it!

 

[bucketboy]

Americans will not adopt the metric system because they don't want to, not because it might be a better system or it would put the whole world under a unified measurement system. The more they think that metric is being forced on them the more they resist, generally if they didn't invent it they don't want it.

You already do use metric..............

How many cents in a dime and how many dimes in a dollar ;D

Bb

 

[John S]

Only the BBC and dressmakers use cm, every one else uses mm up to 1,000 then it's metres.

Fractions are Ok but in 60 odd years of being around machine tools i have never seen a dial in fractions.

In imperial you have two measurements 31/64" is equal to 0.4844. Possibly a drawing says 31/64" but you have to turn or mill to 0.4844, room for error there.

In metric that measurement is 12.304, period, full stop, end of story, no room for error.

John S.