I am working on another renovation and doing a lot of measuring, cutting and placements. I have metric on my Fat Max tape and I just stumbled into using it. Those boys might be on to something there.

Example I have a wall 6 feet 6 3/4" long and I want 4 evenly spaced lights on it (5 equal intervals counting the ends)
I could convert this all to 1/4" segments and divide that, then reconvert back to inches (like they taught you in school) or I could just say this is 200 cm, divided by 5 so I measure 40 cm between each light and off I go.
At a certain point I am really only using the metric scale as an arbitrary decimal measurement but it does work pretty neat.
Since things like "1/2" plywood, trade marked '15/32" is really 12mm this transition may even start to get easier.

"Them furriners" may win me over here.

An old draftsman (modified for carpenters) trick is to hold your tape at an angle so that the overall length is some even number that you can divide easily. Mark those points along the tape, then use a plumb line to transfer those makrs to the top of the wall. 80" would work nicely in your example.

Sounds weird...but works every time.

One problem with metric in Canada is that so much comes from the US. I once put up pegboard for store shelving that hung on rails on the wall. The pegboard was metric and the shelves were 4 feet, so each pegboard had to be cut by a few millimeters.

Next, the writers of the Canadian Electrical Code did a soft conversion. A hard conversion is when the gas is sold by the litre. a soft conversion is when devices in boxes that are greater than 2.54 centimeters (1 inch) deep have the volume calculated in litres. Try measuring .4 of a millimeter.

Be careful what you wish for. You could be carrying two sets of sockets and hex wrenches and screwing up measurements that need to be converted.

We have been carrying two sets of sockets for 20 years. Anything we get from abroad is metric.

Yes, I know that working on my Ford truck requires 2 sets of sockets.

I found out the hard way that the stern ground block on my boat had metric terminals! Beside being in a bxxxx location, it's metric, & I had no metric nut drivers!!

PS: That afternoon I had to get metric nutdrivers!!

And the reverse is true here in France where metric measurements were "invented". Most board materials, esp. US or Canadian softwood ply, come in 1220 x 2440 [8'x4'] sheets, but are 'metric' thicknessed! The UK went metric in the late sixties, including our money, but we still officially use the pint, the mile, yards, horsepower and a few others there. The money was more difficult to get used to than you can imagine, and forty years later, I still confuse my kids by talking in shillings, tanners, bobs, florins, pounds, tuppence, new-pence, stones, euros and both old and new francs- plus stones, bushels and fluffteenths.

Most UK tapes have both imperial and metric markings and I use both with ease, being an adult when we changed over, but also because whenever you want to measure in an awkward corner the markings are invariably on the wrong side of the tape! Imperial is far from dead, because it's designed around practical human units. Here in France over 200 years after forced metrication of everything, you can still buy market vegetables in livres, and buy a tv in pouces.

In a sense, the USA is metric, in that the official standards refer back to the metric system. Like "an inch shall equal 2.54cm".

Nowadays, stuff in the supermarket has metric measurements alongside the English units. Which makes things easier for me, as I can never remember how many oz's to a pound (is it 12 or 16?) or what a fluid oz is, or how many to a half gallon. And I grew up in the USA. With grams or liters, it's easy.

The US has been the biggest obstacle in getting the known universe to adopt metric. Once we get you to accept the rest of the world has changed and that your steadfast adherence to an archaic English system (wasn't there a revolution on following English standards?) you and the rest of the work will save money and it will be easier to sell American Cars in Europe.

We tried to go full metric in the 70's but the huge amount of US manufactured goods stifled that.

Technically it's called the Imperial system.
I guess it was named back when England's head was big and they had outposts and colonies all around the globe.

With practice, it works fine...after all, we went to the Moon several times using mils (thousands of an inch). We even left 3 junked cars up there.

Any system of measurement works as long as the guy making the other part also uses it. There is a big cost when one person uses their economic power to use one standard and everyone else uses another. Maybe when you finish off your economy properly we will be able to force metric upon you. Until then I guess we will buy two sets of tools and pray your pilots convert litres to pounds correctly. There isn't always a Canadian airport to catch the mistake ;-). Think how much cheaper your Chinese made in America Harley parts would have been if they used metric fasteners. Remember VHS vs Beta. Beta was better but the world chose VHS and even the most powerful consumer electronics company lost a lot of business in that war. You can be sure that even with it's world directing economic power that the US looses a lot of the world market by insisting on inches. Even on that specific scale 150mm sounds bigger than 6 inches. The adds would say add 50 by taking these little pills.

I get the impression that at last the metric system is starting to creep into the U.S, and a good thing too.
I've noticed on some television shows that some cars have the speedometers calibrated in km/h as well as mph. I sometimes wonder if this is an attempt to get U.S citizens used to metric units in a practical sense. I was told by a U.S school teacher on a visit that the metric system is taught there in schools.
Anyway, having grown up in Australia as the Imperial system was phased out starting in 1970, building materials still described in imperial units have almost gone.
I work on mechanical things and I'll tell you what, using imperial spanners is a pain. Having to stuff around with fractions working out what the next size spanner is requires converting back and forth between eights, sixteenths and quarters. Whereas if I want the next size up from 14mm, I look for 15mm; easy.

I suspect that has to do with so many building codes here that require studs on 16" centers and roof trusses on 24" centers. 4' and 8' just work out so well there.

Oddly enough Greg,
The centimetre, is the sort of "odd one out" over here.
I think the last time I used cm's was way back in Primary school.
Everyone that I know uses the milli-metre over here to measure things to any degree of accuracy.

In a way, the US has been incorporating Metric "Terms" into standard values for quite some time; i.e.:

• "Kilo" Volt-Amp,
• "Mega" Watt,
• "Milli" Amp,
• "Deci" Bels,
• "Micro" Farad.

In High School Physical Science, Metric values were used universally, without any requirements to convert results from SI Units to Imperial Units.
This was a great way to "become Metric fluent".

Most of the Construction-based Technical Documents (including the NEC), include SI values and "Standard Imperial".

Electrical Engineering is SI based, requiring Unit Conversions where applicable.
For me to determine wavelength, it is much easier to consider the value of "C" as 300,000 KM/S, as opposed to 186,000 Miles/S.

Illumination quantities - AKA "Lighting Levels", may be expressed as:
* Footcandles (Fc)
or
* Lux (Lx)
with a very simple conversion factor.

10 Fc = 100 Lx

To convert Lx to Fc:
Move the Decimal Point one space to the Left.

To convert Fc to Lx:
Move the Decimal Point one space to the Right.

Scott

I'd just like to add that we English did not invent the inch, even if we are big-heads about inventing everything else including the internet! Imperial simply refers to the 1824 Act of Parliament which attempted to make measures to be the same throughout the UK & Empire. By then the US had become independant, which is why your gallon is smaller than ours! The Act was primarily to stop people getting ripped off by short weights and confused by a plethora of different gallons, pints etc. The inch/foot can be traced back to before the time of the pharoahs, [3500BC] and is related to the cubit, [= about 1'6"]. The Romans bought the system to Britain in 44AD. It is in fact postulated that the cubit may have had its roots even earlier, in neolithic times. The builders of Stonehenge must have had measuring tools! One theory is that of the neolithic 'Venus Pendulum'. By timing the passage across the sky of Venus, using a pendulum bob over a 366 day cycle, you can not only get an accurate length base, [the neolithic yard], but an accurate astrological clock too, and discarded pendulum bobs are found at many megalith sites all over Northern Europe. Which is a bit more romantic than 1/10 millionths of the distance from the North pole to the Equator, via Paris, and then getting it wrong! I say long live the barley-corn, inch, foot, yard, pole, perch, furlong, chain, fathom, mile & league!

That's pretty much because electricity was discovered and developed after the Metric system was invented. Else we'd be dealing with Imperial measures of voltage, like "1 zapper = 2.54 volts" "We have 47 zappers on our powerlines in the USA". Thank heaven we don't have this silliness!

I think a lot of it boils down to the fact that the decimal system is in most cases considerably easier to grasp than fractions, except for the most simple ones like half and quarter (useful for measuring time, which isn't metric at all *g*). To me the idea that the human is a decimal being always made a lot of sense - we do have 10 fingers and toes each.

Those prefixes actually predate metric and even the birth of Christ. They are from ancient Greece.

Our ancestors were not a bunch of idiots with 12 fingers, they chose base 12 for practical reasons. It divides up better. 12 divides by 2, 3 and 6 in whole numbers. 10 divides by only 2 and 5.
Our old British money was base 12 too- 12 pennies per shilling, making shopping easy.
They still sell eggs in dozens, even in France!

If they really wanted something that would stand the test of time they should have gone base 16

I am to old to try and change.

@Alan: all countries that I know of have rounded their pre-metric units. The German Pfund, the Dutch pond and the French livre are all 500g rather than some odd number. None of those units is used officially, but most people know them and use them in everyday communications, just like the dag (Dekagramm or short Deka) in Austria and Hungary, which is a metric unit but as far as I know not used anywhere else. The "douzaine" is the only non-decimal unit still in use in Continental Europe as far as I know (except seconds, minutes, etc. of course *g*).

American cars have had mph /kph speedometers since maybe the seventies. Only really used if you drive into Canada or Mexico.

I have worked on projects in different countries and the ability to work in different units is more than just being able to make conversions. For instance, you may start with basic manufacturing stock of 0.500 inch (12.7 mm) if designing or making something in the US. But in the metric countries, that is not their standard, so you start out with 13mm. It doesn't make sense to go to the next SI size up and machine down to 13mm in US. So until the basic manufacturing processes are changed to "hard Metric", the products we design and the tools we use will seem to follow the basic manufacturing building blocks. It would be great for everyone to be on the same measurements – and the trend is toward metric. The decimal inch does everything pretty well, that is why it has not gone away yet. The liquid measurements we have (other than ounces) is a real mess, and would be good riddance.

Tex, there are still a lot of unconverted non-metric things, as you say.

The Revolutionaires did try a 10 hour clock, [1793-1806] but it proved short lived.


click to enlarge

They also had three 10-day weeks in each of the renamed the 12 months- [another twelvism that survived]! This caused riots when the sans-culottes realised they'd just lost their weekends off! They got round the inconvenience of the Earth continuing to rotate at the same speed after 1793 by slotting in 6 or 7 special days at the end of the months.

There are a few more. The old pre-revolutionary pipe threads have not changed - metric pipe threads are in fact interchangeable with BSP for domestic work. Funnily enough, the American National Pipe threads are not interchangeable even though dimensioned in inches. I wonder if it was the cost of replacing all the French plumbers' taps and dies? As a lad in the machine-shop, all our lathes had a 127-tooth wheel for screwcutting [nearly] true metric pitch threads on British machines.
'G' as you say refused to be neat and tidy, insisting on accelerating at 9.81m/sec2 or about 32 ft/sec2. As a matter of fact the poundal and slug, engineering calculation units based on Earth's 'G' cannot be termed Imperial, for they were invented long after the 1824 Act.

And finally Gold. Still traded in ounces, troy of course. At 12 ounces to the pound!

Ahh yes Alan,
The metric clock!
I have one of these here, that I bought back in 1986.
If you married one of them movements, with the backwards face clocks that were big in the 80's, I bet you could have some real fun down at the pub.

Not forgetting the 12 Disciples, the Dirty Dozen, the 12 Good Men [or Ladies] and True in our Courtroom juries, the 12 Signs of the Zodiac, a Dozen a Day [ = 0.000138888889 hertz! ], or a dozen red roses for that special lady.

Let's be honest, the 10 Days of Christmas just doesn't sound right either, does it?

12 months ,12 tribes

12 pack

the most important # two twelve packs to a case 24 hours in a day how convienent

I couldn't help reminiscing on this topic. I can remember back when I was just a young tater tot in the early 1970's, the sense of sudden urgency instilled by our slightly hippie math teacher that "the metric system is coming... the metric system is coming... get ready... learn it now or you'll be left behind"

Seems that after a couple of months or so, the fury just sort of died down.
Now here it is, close to 40-years later and we still have to buy both individual Metric and SAE tool sets or combination sets of every type open end, box, combination wrench, socket, hex head wrench, tap and die ever known to man.

I think it's relatively safe to assume that by now we've all pretty much become accustomed to it and it just seems natural, almost expected to see many types of equipment using both Metric and SAE fasteners.
In retrospect, it could probably be seen as a brilliant marketing strategy by the tool and die manufactures.

The only ones who embraced metric right away were the liquor distributors. A "fifth" of whiskey became a 750ml, just a little smaller don't you know.

Never thought to much about it just picked the "big" bottle

When I was at Polytech, doing the first of many "Block Courses" during my apprenticeship, I had an English engineering tutor, that spoke only in Imperial.
That was OK, you could easily convert to metrics, with what he was saying.
That was until we started using machine tools like a lathe.

Now, a lot of you Electrical guys might be asking, why on earth is an electrical apprentice, being taught "mechanical engineering" stuff?

Simple answer is, so that you are aware of what other trades are doing.
Lathe work and other such engineering skills are great to have, it makes you more employable as a staff member.

If you ever get the chance to have a go at or be taught engineering fabrication, grasp it with both hands and take it.
A person that is only taught one trade, is pretty much stuck in that trade and within it's boundaries.
And to a certain degree, it's "wage value"
The more you can do, the more you'll earn.

{Greg, sorry to take this off-topic from Metrics}

That's OK
I have always seen the value in having a lot of cards in my wallet. In an environment like this, the more you can do, the better chance you have of finding someone to pay you to do it.

Back on topic, I showed the tile guys my metric trick today when they were trying to center up a section of tile and doing some complex math with 1/8th and 1/16th inches. The fact that the tile was metric to start with made it a lot easier. They used my fat max and say they are buying a tape with metrics on it.

I do engineering calculations almost exclusively in metric. I'll convert imperial to metric, do the calcs, and convert back. But I just can't "think" in metric as far as estimations, go. You say 70F and I know what you're talking about; you say 20C or 120kph and I have to mentally convert to F or mph.

Well that's just what you're used to or not - for me it's the same the other way round. Unless people cling to something because it has always been that way and is regarded as a valued tradition, changeover could happen within a generation when kids are taught "the other way" at school.

@Trumpy, when I went through my apprenticeship in the late 80's, the first year we were sent to a trade school. The first 6 months where spent rotating through all the trades to learn the basics. Welding, milling, sheetmetal etc.. When I went back to my employers, we where expected to build any brackets, boxes etc we needed to do our electrical work. I still use them skills and enjoy the hands on aspect.

Back on topic, when I left England to come stateside, I had the fun of learning imperial measurements, and boy do I understand fractions better too