Easy Metric Tutorial?
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SittingElf
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Yikes! Just reading through this thread is making my brain hurt! [eek]
What I really wish is that the U.S. had stuck to its guns and converted to the metric system years ago when they had set a date for that to be the only system taught in schools. Unfortunately, there were too many parents and school boards that strongly resisted and date after date came and went. Metric vs. Imperial confuses me just as it does millions of other Americans... but even at 57 years old, I'm willing to bite the bullet and convert... if everyone else will!
I would be willing to dump all my imperial tools and measuring devices in the trash if we set a real date; had classes and tutorials available; and stopped selling imperial devices and tools. We Americans will HAVE to convert at some point, and this mixed system we're dealing with now is clearly more painful than finally taking the leap and just getting it done. [2cents]
What I really wish is that the U.S. had stuck to its guns and converted to the metric system years ago when they had set a date for that to be the only system taught in schools. Unfortunately, there were too many parents and school boards that strongly resisted and date after date came and went. Metric vs. Imperial confuses me just as it does millions of other Americans... but even at 57 years old, I'm willing to bite the bullet and convert... if everyone else will!
I would be willing to dump all my imperial tools and measuring devices in the trash if we set a real date; had classes and tutorials available; and stopped selling imperial devices and tools. We Americans will HAVE to convert at some point, and this mixed system we're dealing with now is clearly more painful than finally taking the leap and just getting it done. [2cents]
jonathan-m
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I think this video explains it really well:
Stephen B
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I do not think it (the video) helps at all, even I was confused, and I have been using and teaching metric systems since 1972. Alex in #41 makes a much better effort. The main problem with the video is that it uses proper fractions rather than decimal fractions to explain a system that is based on decimal fractions.
And like Alex, at least when understanding measuring in building and carpentry, it is better to start with mm and build that understanding up to CM and Metres, as 1, 10, 100 and 1000.
Also as stated before on this and other threads back in May/June, you will be less confused in building and carpentry if you stick only to mm. A 2700mm wall height is better expressed as 2700mm, than either 2.7metres or 270cms. Hence on house plans in Australia you see measurement in mm. This is reinforced by the layout of most measuring tapes so there is less margin for error.
And like Alex, at least when understanding measuring in building and carpentry, it is better to start with mm and build that understanding up to CM and Metres, as 1, 10, 100 and 1000.
Also as stated before on this and other threads back in May/June, you will be less confused in building and carpentry if you stick only to mm. A 2700mm wall height is better expressed as 2700mm, than either 2.7metres or 270cms. Hence on house plans in Australia you see measurement in mm. This is reinforced by the layout of most measuring tapes so there is less margin for error.
jonny round boy
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That video does explain it quite well, but to me it makes it slightly too complicated by using the Deka and Deci prefixes. In my experience those two are never used. The Kilo prefix is used for grams and metres, but not so much for litres (most people would refer to 1000 litres as being 'a thousand litres'; they would not say 'a kilolitre'.
Since that video includes volume/capacity (litre) and weight/mass (grams), I'll take this opportunity to point out that the three measurements are also inter-related:
Note: The weight/volume is dependent on the specific gravity of the liquid (water, being the most common liquid on earth, is used as the basepoint & has a specific gravity of 1). For a lighter liquid such as gasoline (which has a specific gravity of around 0.737) 1 litre would weigh 0.737kg.
Edit: Stephen posted whilst I was typing. I agree with him on the whole mm issue. Best to stick to mm for woodworking/joinery, rather than using cm or m.
Since that video includes volume/capacity (litre) and weight/mass (grams), I'll take this opportunity to point out that the three measurements are also inter-related:
- 1 litre of pure water weighs 1 kilogram; 1 litre also fits exactly in a cube of 1/10th of a metre (100 x 100 x 100mm, or 10cm x 10cm x 10cm).
- 1 cubic centimetre (or cc) is exactly the same volume of 1 millilitre, and weighs 1 gram.
- 1000 litres (or 1 kilolitre) is the same volume as 1 metre cubed (1 x 1 x 1m), and that amount of pure water would weigh 1000 kilograms, or 1 metric tonne.
Note: The weight/volume is dependent on the specific gravity of the liquid (water, being the most common liquid on earth, is used as the basepoint & has a specific gravity of 1). For a lighter liquid such as gasoline (which has a specific gravity of around 0.737) 1 litre would weigh 0.737kg.
Edit: Stephen posted whilst I was typing. I agree with him on the whole mm issue. Best to stick to mm for woodworking/joinery, rather than using cm or m.
As for knots and nautical miles (mentioned earlier in the thread), it's actually quite interesting and logical.
1 nautical mile = 1852 meters, or more exact 40000/360/60 kilometers. This comes from a standardized measurement around the globe (which actually isn't completely spherical). 360 degrees around the globe is 40 000 kilometers. I.e. 1 nautical mile is the length of one degree minute (1/60 of a degree) on the surface of the earth.
1 knot is 1 nm/h, i.e. roughly 1.85 km/h.
The nice thing about this system is that it's easy to do the math at sea. It will take one hour to travel one degree minute at a speed of one knot.
A "land mile" has nothing to do with a nautical mile to my knowledge.
//Michael (a metric guy)
1 nautical mile = 1852 meters, or more exact 40000/360/60 kilometers. This comes from a standardized measurement around the globe (which actually isn't completely spherical). 360 degrees around the globe is 40 000 kilometers. I.e. 1 nautical mile is the length of one degree minute (1/60 of a degree) on the surface of the earth.
1 knot is 1 nm/h, i.e. roughly 1.85 km/h.
The nice thing about this system is that it's easy to do the math at sea. It will take one hour to travel one degree minute at a speed of one knot.
A "land mile" has nothing to do with a nautical mile to my knowledge.
//Michael (a metric guy)
SittingElf
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Here's the problem for we Imperialists!
We have since birth been taught and functioned in imperial measurements. As a result, we THINK in imperial. If you say it's a foot long, my brain instantly knows roughly what that size is. Three inches? No problem, I can "see" that. But... if you say its 200mm.... we imperialists have virtually no idea what that equates to. Therein lies the problem with conversion. To most of us, if you say one meter, we THINK three feet, though that is not anywhere near accurate.
How long is a mile? If you say you hiked three kilometers, we tend to think of that as probably a little less than three miles, even though it is much closer to two.
These are the conversions...not only on paper, but in our heads that we have to get through in order to effectively and eventually convert to metric.
As I said earlier.... thinking about this stuff makes my brain hurt! [unsure]
We have since birth been taught and functioned in imperial measurements. As a result, we THINK in imperial. If you say it's a foot long, my brain instantly knows roughly what that size is. Three inches? No problem, I can "see" that. But... if you say its 200mm.... we imperialists have virtually no idea what that equates to. Therein lies the problem with conversion. To most of us, if you say one meter, we THINK three feet, though that is not anywhere near accurate.
How long is a mile? If you say you hiked three kilometers, we tend to think of that as probably a little less than three miles, even though it is much closer to two.
These are the conversions...not only on paper, but in our heads that we have to get through in order to effectively and eventually convert to metric.
As I said earlier.... thinking about this stuff makes my brain hurt! [unsure]
Stephen B
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It's OK. Just take a pain killer!
Then buy a metric only tape measure, Festool of course, and in Germany. [smile]
I understand your pain, as a school student I was taught imperial systems. In 1972, as a young teacher graduate I found myself having to teach metric.
I think your real problem is the one you have stated yourself. The US for its own reasons has not mandated effective change, so now the metric system is seen as an imposition placed on Americans by the international community. Quite naturally this only fosters further resistance. And let's face it, imperial systems have served your country well at least historically in its growth and development.
Then buy a metric only tape measure, Festool of course, and in Germany. [smile]
I understand your pain, as a school student I was taught imperial systems. In 1972, as a young teacher graduate I found myself having to teach metric.
I think your real problem is the one you have stated yourself. The US for its own reasons has not mandated effective change, so now the metric system is seen as an imposition placed on Americans by the international community. Quite naturally this only fosters further resistance. And let's face it, imperial systems have served your country well at least historically in its growth and development.
stvrowe
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SittingElf said:
I think you hit the nail on the head. I remember back in the 1970's speed limit signs and road signs having both mph and kph (as well as miles and km) to prepare us for the great metric transition that never happened. By the mid 1980's these dual unit signs all disappeared. My theory for this disappearance is that someone looked at the total cost for replacing all the milemarkers with kilometer signs across the nation and it was just too expensive. [big grin]
However, I am not so convinced of the metric purity of the various countries. Several years ago I spent some time in Switzerland for one of my projects and during some free time, went through the hardware department of a COOP store. I expected to find 8mm shank router bits and I did. What surprised me was the number of router bits available that had 12.7mm shanks. Now you can call that metric all you want but, that is still a 1/2" shank router bit. I guess for every metric measurement, there is an equal but opposite imperial measurement. [laughing]
SittingElf
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Stephen B said:
Yup... already bought one, and it's both imperial AND metric. Nice tape measure and significantly cheaper in Germany. €10,80 incl VAT vs. $25.00 in the USA, which works out to just about half the price of USA sales. I won't be bringing more back next time in Germany though, because I only bring NAINA items and the tape measure is available at all USA Festool Dealers and Amazon.
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seth
and you'll get paid in beaver pelts & chickens
and you'll get paid in beaver pelts & chickens
pugilato
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In Puerto Rico, mile markers are in Km. So if the road sign reads 10 to your town, that is Km. Divide it by 0.6 and you got miles (I usually divide by half and give it a bit more). To add to the confusion, speedometers are in mph. Kilometers and hectometers are used for distance measurements. For example, I live in Km 3.2 of a state road. That means Km 3 Hm 2, so an hectometer is a tenth of a Km, I think. I have talked with fishermen who still use fathoms (brazas) to measure depth. And a client asked me to build a horse stable that would fit a horse so many hands tall. And if you ask for shorts on a smoke, you ask for the "two", which means two fingers.
In truth, its not that hard to figure out, math is easier with metric, but once you are used to it, it is not that hard with fractions.
In truth, its not that hard to figure out, math is easier with metric, but once you are used to it, it is not that hard with fractions.
SittingElf
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SRSemenza said:
Funny you should say that. I'm in the middle of cutting insulation foam board for my garage doors...and it is smoking hot and humid here in Florida. So.... I just started a Yuengling Black & Tan just as I read this post!! [big grin] Coincidence? Nah... must be mind control!
By the way.. off topic, but the Carvex PSC420 with the T155 blade is AWESOME for cutting these foam board! Man!! I started with a box cutter making a huge mess before I had my "DOH" moment and realized I had that blade in my assortment for the Carvex. Making the work 100 times easier!
Darn... beer is almost done... and a second one would keep me from finishing the insulation job. Oh well... later! [big grin]
Peter-kenny
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I'm confused I no a inch is 25mm but what this suppose to be----> 1' ??? If a 1" 25mm and the other is 30??? What's that all about?? [huh]
Stephen B
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Peter-kenny said:
1" is 1 inch
1' is 1 foot
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Now those beers consumed in North America while I slept. How many mls in the can? [smile]
---------------
"seth
and you'll get paid in beaver pelts & chickens"
Sounds fair enough!! [big grin] Could be that a new Kapex would be 1 metric ton of barley!!
Acrobat
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One can get rather technical, but to help the original poster.....
I try to visualise lengths and sizes in everyday terms, so understanding that you know feet and inches already......in simple terms...and everyday usage...
1 foot or 12 inches = 300 millimetres approx (mm's), give or take a few mm's. 300 millimetres is also 30cm's "centremetres".
10mm = 1cm.
100mm =10cm.
1000mm is 1 Metre.
Metres are used in metric when sizes are getting large, say to describe a deck area e.g. 6 x 3 metres. You'd be used to saying it in feet and inches.
1 inch approx 25mm (25.4 to be precise).
4 inches = 100mm approx
6 inches = 125mm approx
A 2x4 piece of lumber is 50 x 100mm
A 2x 6 is 50 x 125mm
A sheet of ply 4' x 8' = 1200 x 2400mm
I have just given approx final measurements so not down to the last mm, but rather to enable one to grasp a size mentally and understand the dimensions someone is talking about.
Just those above will quite likely get you through most everyday tasks until you get a feel for it. The hardest part is the going back and forth, easier to work only in 1 system.
I forgot some common fractions in imperial use:
1/4" = 6.35mm or 6.4mm
1/8" = 3mm
1/2" = 12.4mm is usually the standard router bit size chose there.
That should do it
Hope this helps and doesn't add to your stress of learning it.
I try to visualise lengths and sizes in everyday terms, so understanding that you know feet and inches already......in simple terms...and everyday usage...
1 foot or 12 inches = 300 millimetres approx (mm's), give or take a few mm's. 300 millimetres is also 30cm's "centremetres".
10mm = 1cm.
100mm =10cm.
1000mm is 1 Metre.
Metres are used in metric when sizes are getting large, say to describe a deck area e.g. 6 x 3 metres. You'd be used to saying it in feet and inches.
1 inch approx 25mm (25.4 to be precise).
4 inches = 100mm approx
6 inches = 125mm approx
A 2x4 piece of lumber is 50 x 100mm
A 2x 6 is 50 x 125mm
A sheet of ply 4' x 8' = 1200 x 2400mm
I have just given approx final measurements so not down to the last mm, but rather to enable one to grasp a size mentally and understand the dimensions someone is talking about.
Just those above will quite likely get you through most everyday tasks until you get a feel for it. The hardest part is the going back and forth, easier to work only in 1 system.
I forgot some common fractions in imperial use:
1/4" = 6.35mm or 6.4mm
1/8" = 3mm
1/2" = 12.4mm is usually the standard router bit size chose there.
That should do it
Hope this helps and doesn't add to your stress of learning it.
Len Kuffert
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Paul G said:
In Canada, we trade too much with the US to have made the switch properly. Land is still often referred to in acres, for example. Lumber exporting being what it is, we are also stuck with imperial there as well. Annoying, but not much to be done at this point. The time for bravery has passed.
