Metric vs Imperial units

[WhiteBlue]

Practically no craftsman in the metric world uses mm. Builders, gardeners, tailors, carpenters and the like use centimeters and meters. Paper based maps use kms and GPS systems use both kms and meters. Architects and real estate agents use square meters and for very big real estate square km. Millimeters are only used by engineers and precision crafts like watch makers. Physicists and micro engineering use micrometers and nanometers. The liter which is the prevalent volume unit is equal to one cubic decimeter and we use hectoliters for bigger fluid containers like barrels. Drinks are measured in milliliters which are equal to a cubic centimeter. Civil engineers calculate earth movements in cubic meters and logistic experts use the same unit for shipping purposes. The myth that any imperial measurement for length, area or volumetric measuring is superior cannot be verified. It is simply not true. The metric system serves all purposes in all walks of life much better and more efficient.

[xpensive]

Very true WB, however my drinks are measured in centiliters, which is 10 milliliters, at the very least!

[WhiteBlue]

Very true WB, however my drinks are measured in centiliters, which is 10 milliliters, at the very least!

Here in Munich at the Octoberfest we have no ml either. The drinks go by the Maß which is a bavarian name for one liter of beer.





I can assure you that people have a very clear understanding how many Maß can be carried and drunk.

[Richard]

My ref to Apollo 13 was about the air filters. They used a mix of round and square air filers.

Builders, gardeners, tailors, carpenters and the like use centimeters and meters.

The architectural drawings I work with are all in millimetres. However, I have found that the Germans and French use the traditional cm, while converts to the ISO system use mm and m.

It is odd checking the fabrication calcs drawings from a German engineer. To my eyes 3,175 is either 3km or 3m, to the German engineer it is 3cm.

[WhiteBlue]

This cm tool would be used by a tailor.



and this one by a builder or gardener.

Architects use CAD software that originated in engineering. That is why you find engineering measures in many plans. But crafts people in every day use would mainly use cm measuring tools that also show mm.



This is a traditional builder's plan showing walls in meters with cm accuracy and areas in squaremeters.

[rjsa]

Just The Problem

Neither the familiar system of Feet and Inches nor the Metric system of meters and millimeters are suited to the type of measurement and calculation woodworkers and other craftspeople use day in day out.

The Solution
A system of measurement that retains Feet and Inches and then divides the Inch into 24 parts.

The Argument
The Metric system excels at smaller measurement while Feet and Inches are better suited to larger. Because of these innate characteristics I have always used both, often in awkward combination. The Metric system’s only real asset is the particular size of the millimeter. This happens to be an ideal “small” unit of measure. Smaller than a 1/16" and larger than a 1/32", it can be distinguished easily without reading glasses while at the same time is fine enough to be a basic increment of woodworking precision.

In every other respect the Metric system is inadequate. There can be no rational argument in favor of a system that divides and multiplies by tens. It is perhaps not surprising that we break the day into 24 hours rather than 20, the hour intoU 60 minutes rather than 100 and so on. By the same token we divide the circle into 360 degrees rather than 100 or 1000. It is because the basic building block of twelve is vastly more versatile than ten, whose capacity for easy division by five and multiplication by ten is a talent I cannot remember ever having needed in 25 years of woodworking. Hell the only reason to post this is to fuel on the fire with a new system.

Feet and Inches supply a manageable series of larger increments. Feet and Inches break up what in the Metric system tend to be long easily corrupted numbers into readily recalled chunks. For example a Metric length of 2286mm equals 7 feet 6 inches. While 2286 might easily become 2268 in our fallible memories, it is hard to not notice 7 feet 6 inches becoming 6 feet 7 inches. The inspired division of the foot into 12 inches rather than 10 allows easy division into halves, thirds and quarters.

The great failing of Feet and Inches is the multitude of unsatisfactory fractions that make addition, subtraction and division an exercise in mental agility and provide ample opportunity for error. Nobody can quickly and reliably add 11 7/16" and 4 5/32" then divide the result by two, let alone three.

With our new rulers all these issues become a thing of the past and we find a system that combines the best of both of the old without any of their failings. This is achieved by employing the 1/24" as the basic increment. The 1/24" is a useful increment in a number of ways. Like the foot, which can be easily divided into halves, thirds, quarters, sixths and twelfths, an inch made up of 1/24th’s can be divided into halves, thirds, quarters, sixths, eights, and twelfths (try that with the metric system). The 1/24" is very close in size to the millimeter and so has the same natural advantage as an ideal small unit. These rulers allow us to take advantage of the largely forgotten 1/24" and elevate it to its rightful place as a core unit of measurement.to confuse the units discussion by introducing bobsrule.

It might be good for woodworking and the legality plank.

And when you have to calculate area (need to square a value) you have to resot to decimal fractions of whatever imperial unit you are using. The system just does not hold whater.

[Just_a_fan]

Builders, carpenters and the like use centimeters and meters.

Not in my experience. In over 20 years in the building industry in the UK - most use metres and millimetres (old guys still use feet and inches or, more commonly, metres and inches!) these days.

Centimetre is a horribly measurement that seems to be favoured in schools but has no place in the real world. I see no point in it - I've seen people write "25.7cm" ; what's the point when 257mm or 0.257m does the job so well?

Indeed, it should be illegal to use centimetres!

[autogyro]

Only time the English went metric sensibly was when we invented the Sten gun for nicking German ammunition in WW2 at 9 mil.
On exercises with NATO there were horrendous problems because of different sizes mainly in guns. The Russians would have laughed right across the border.
Anyway whats wrong with the old Royal Navy four inch, kept the peace for years.
Pity the Americans didnt scale to the .5 inch muskets the taliban use. They would probably not be leaving today.

[WhiteBlue]

Builders, carpenters and the like use centimeters and meters.

Not in my experience. In over 20 years in the building industry in the UK - most use metres and millimetres (old guys still use feet and inches or, more commonly, metres and inches!) these days.

Well, the UK is hardly the source of best or traditional practice of metrics. So I refrain from further comments.

Centimetre is a horribly measurement that seems to be favoured in schools but has no place in the real world. I see no point in it - I've seen people write "25.7cm" ; what's the point when 257mm or 0.257m does the job so well? Indeed, it should be illegal to use centimetres!

Centimeters make plenty of sense for all craftspeople as I have already shown. It is the closest unit in size to an inch and that has its uses as well.

[Just_a_fan]

Well, the UK is hardly the source of best or traditional practice of metrics. So I refrain from further comments.

My point was that your attempt to suggest a universiality of the measurement system you mentioned was incorrect. No further comment is required, thanks.

[Richard]

Well, the UK is hardly the source of best or traditional practice of metrics. So I refrain from further comments.

You missed the point. Countries new to ISO use mm and m, whether architect, engineer or surveyor. For example my recent projects in Middle East and Asia, as well as UK. I have only come across cm used in professional design in Germany & France.

[xpensive]

I wouldn't know about architecture or anything, but as long we're talking machine-design, there's only millimeters.

Remember when Montreal was granted the 1976 Olympics and outsourced the architecture for the stadium to a French company, which sent the metric drawings to a Canadian contractor. This being the early 70s, with mobsters, unions and all, everything that possibly could went off the road!

[PlatinumZealot]

Builders, carpenters and the like use centimeters and meters.

Not in my experience. In over 20 years in the building industry in the UK - most use metres and millimetres (old guys still use feet and inches or, more commonly, metres and inches!) these days.

Centimetre is a horribly measurement that seems to be favoured in schools but has no place in the real world. I see no point in it - I've seen people write "25.7cm" ; what's the point when 257mm or 0.257m does the job so well?

Indeed, it should be illegal to use centimetres!

Centimeters work best for stress calculations I find.

Hey, suppose there was a GPS system that uses inches, yards, furlongs and miles? Craziness if you ask me. Now imagine kilo-inches and kilo-feet.. lol..

[Pup]

The architectural drawings I work with are all in millimetres.

That is the standard.

This is a traditional builder's plan showing walls in meters with cm accuracy and areas in squaremeters.

That plan looks more like something they used to jot down existing dimensions, so I wouldn't hold it up as an example. At least I hope that's what it is, because it is sheet.

[Pup]

I think nature intended for humans to use the metric system.
The density of water is roughly 1000kg/cubic meter.
The viscosity of water is 0.001 pascal second at 20 degrees CELSIUS.
Water freezes at 0 degrees C. It boils at 100C
Atmospheric pressure is about 100 kPa

Nice clean easy numbers.

I think man intended for the metric system to be based on water. Therefore, nice clean easy numbers, when one is measuring water. When one is measuring things we use from day to day, things that should correspond to human proportions, those numbers aren't nice clean and easy at all.