Metric vs Imperial units

[Just_a_fan]

I disagree.
Most people use cm in normal life. It handles just better somehow.

And yet a number of people have come on here and said that cm isn't used. Perhaps it is in more common usage in Germany (certainly from WB's and your own posts that seems to be the case) but in lots of other places it isn't.

Thus "most" people probably don't use cm. Or at least, not as many as "most" might suggest anyway.

[Mystery Steve]

Awsome as long as you stick to sandwiches rather than engineering perhaps...but seriously, Subway in Sweden uses cm.

[youtube]http://www.youtube.com/watch?v=fKLNp890 ... re=related[/youtube]

[Richard]

mep - Agreed, humans tend to use traditional human scale dimensions. That's cm for you, inches for me.

However in countries where the metric system is new, the technical data is usually in mm, that's because they started with a clean slate. Countries that traditionally used cm tend to stick with cm for technical data because it still works - there is little reason to change.

The post is a good example. WB posted the example of Germany using cm, meanwhile Royal Mail uses mm.

http://www.royalmail.com/portal/rm/jump ... d=47500706



xpensive - A foot long torpedo of salted, sugared, damp polyfilla & card from subway is still a foot in the UK. What dimensions are used for pizas in Sweden? Also, how big is a tin of tomatoes or vegetables? Here they are 440g, ie 1lb.

[marcush.]

I remember when we had a carpenter doing some work in a design-office where I was active in the 80s.

Carpenter finds a 100 mm gauge-block on my desk, why he goes;
- What's this shiny thing?
- It's a 100 mm gauge-block.
- So?
- I's a measuring device, we know it's xactly 100 mm long.

Carpenter takes his folding ruler, measures the block and says with a surprised voice;
- I'll be darned!

tbh i know NOBODY who thinks in mm (apart from the engineers and some machinists)
and with architects..mm are you sure? that poor devil will get lynched arriving with working plans in mm ,rest assured ...or at the very least something will be wrongly executed ...because someone was irritated..
For sure the workers will need ages to complete their work.
HORSES for courses ...thats my view of it .

[mep]

xpensive - A foot long torpedo of salted, sugared, damp polyfilla & card from subway is still a foot in the UK. What dimensions are used for pizas in Sweden? Also, how big is a tin of tomatoes or vegetables? Here they are 440g, ie 1lb.

I think its the same here. Possible even more. I guess he is peaking about the whole bread (both sides). Anyway I don't understand why people like it so much because its to expensive for just a sandwich (around 8 Euro). In normal shop you get sandwich for around 2 Euro.
Ohhhh damn where this will lead to? We are talking about sandwich sizes now.

Back to topic.
When I go to study in England do I need to learn imperial units?
I am not very keen on calculating with hands and feed.

[DaveW]

Here they are 440g, ie 1lb.

Been shopping at Tesco again, Richard? (Apologies).

[Pup]

I disagree.
Most people use cm in normal life. It handles just better somehow.

And yet a number of people have come on here and said that cm isn't used. Perhaps it is in more common usage in Germany (certainly from WB's and your own posts that seems to be the case) but in lots of other places it isn't.

Thus "most" people probably don't use cm. Or at least, not as many as "most" might suggest anyway.

I don't think anyone is saying cm aren't used (I hope not), nor that they're not a far more common dimension. WB's outlandish assertion was that mm weren't used except in specialized areas like watchmaking. That was a stupid comment, justly rebuked. And then he pulled photos from the weekend-warrior toolkit to prove his point, which just made it all just funny.

Sure it's silly in one respect that architectural plans are done in mm, but the rationale is that decimal points can easily be obscured on drawings. You'd think errors like that would be obvious, but people do some stupid things when they're just following plans. We all saw Spinal Tap, right?

Just for the record, I know an old school furniture guy here and most of his tools, antiques in large part, have measurements to the 1/125th of an inch. And he says he interpolates between them to be more accurate. Judging by some of his inlay work, I don't doubt it.

[xpensive]

@ Richard;
A whole sub at Subway is indeed "30 cm", as for pizzas we don't have measurements, but in Norway they use cm. A can of tomatoes is 440 grams, while a "Quarter pounder", 113.5 gram, is called a QP and not that royale-thing for crying out loud.

Everything sold at IKEA is measured in cm, perhaps not so everywhere in the world? People's height and waistline is cm.

[Pup]

tbh i know NOBODY who thinks in mm (apart from the engineers and some machinists)
and with architects..mm are you sure? that poor devil will get lynched arriving with working plans in mm ,rest assured ...or at the very least something will be wrongly executed ...because someone was irritated..

I'm sure - I'm an architect. See my last post for why we do. I say we, though I use feet and inches myself. But when I worked for a firm that did gov't work, we had to use SI, in mm. What might get an architect lynched, of course, is expecting that level of accuracy in the field, at least for most things. But when it comes to finish work, 1mm can be on the edge of sloppy at times.

I'll give the final word on this to AGS:

Metric specifications should use "mm" for almost all measurements. The use of mm is consistent with the dimensions specified in major codes, such as BOCA and NEC. With the use of mm, the decimal point is used when extreme precision is needed. Meters may be used only where large, round metric sizes are specified. Centimeters shall not be used in specifications. This is consistent with the recommendations of the AIA and ASTM.

So there.

But what I still can't understand is why some people are equating a particular SI unit to accuracy. The only difference is where you put the decimal.

[WhiteBlue]

I hope that one day in my lifetime we can switch to metric in the States.

However, at the end of the day, if I want to build a fence around my house, I don't care what you use to measure distances and materials. As long as the end result is what I want, i'll be happy.

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.

WB's outlandish assertion was that mm weren't used except in specialized areas like watchmaking. That was a stupid comment, justly rebuked. And then he pulled photos from the weekend-warrior toolkit to prove his point, which just made it all just funny.

I don't understand how things always get distorted and why we need personal attacks (as bolded) to discuss such issues. Jddh1 brought up the issue that tape measures and and folding gages are still imperial in the US and that building materials for his fence are still sold in imperial dimensions.

I have added a round of observations how people tend to use adequately sized units for the job at hand. It is also undeniable that most households own a tape measure or folding ruler (in inches or cm) and that very few own a laser meter or a slide gage. Such expensive precision measuring tools would be in m or mm. The practice reflects my observation that in everyday use (not using CAD or engineering methods) the public tends to use inches and cm.

I actually wonder what tools mail customers in the UK use to check their items for mailing. Probably they use cm tape measures that have subdivisions in mm or Mom grabs the 30 cm plastic ruler that her kids use in school.



History of rulers:



A wooden carpenter's rule and other tools found on board the 16th century carrack Mary Rose.

Rulers made of Ivory were in use by the Indus Valley Civilization period prior to 1500 BC. Excavations at Lothal (2400 BC) have yielded one such ruler calibrated to about 1⁄16 in (1.6 mm). Ian Whitelaw holds that the Mohenjo-Daro ruler is divided into units corresponding to 1.32 in (33.5 mm) and these are marked out in decimal subdivisions with amazing accuracy, to within 0.005 in (0.13 mm). Ancient bricks found throughout the region have dimensions that correspond to these units.
Anton Ullrich invented the folding ruler in 1851.

Anton Ulrich's company

[Richard]

A can of tomatoes is 440 grams.

Yup, I think the whole world buys tinned produce by the imperial pound. Even the French.

architects..mm are you sure? that poor devil will get lynched arriving with working plans in mm ,rest assured ...or at the very least something will be wrongly executed ...because someone was irritated..

Which is pretty much happened when German contractors started on some my buildings in the UK and US. Only time I've seen cm on technical drawings

Lets not get onto 120V and 240V ....

[Richard]

Oh, and people do make errors by units of 10 when confronted by a different system of units. Sometimes it can be fatal ...

http://www.guardian.co.uk/society/2010/ ... ed-patient

[aral]

A can of tomatoes is 440 grams.

Yup, I think the whole world buys tinned produce by the imperial pound. Even the French.



Lets not get onto 120V and 240V ....

Travelling the continent a lot, I find your comment about the French, most odd. They do not know what an English pound is. And go into any timber store, all timber is now sold in metric, although some go by the nearest imperial measurement. i.e timber at 50mm by 25 mm is known as 2 by 1, but 50mm is NOT 2 inches, ask any engineer!

[Pup]

Of course, in the US, neither is a 1x2, which is 3/4"x1 1/2"

Lumber dimensions are their own separate world.

1x's are always 3/4" thick. If you want something that's 1", then you ask for a 5/4 board. Widths from 2" to 6" are 1/2" short, so a 2x4 is 1 1/2" x 3 1/2". Above 6", they're 3/4" short. A 3x12, then, is 2 1/2" x 11 1/4".

Oh, and a 10' stud is 9'-8 5/8" long.

[mr moda]

I can feel a graph of some description charting the measuring tools of the ages being posted soon.