Imperial or metric?

[Bill McNiel]

I've gone almost totally metric in the last year, my most trusted tape measure has both systems. I've found it easier to divide metric numbers and a millimeter is more accurate than 1/16". Much easier to figure proportions/dimensions when converting preliminary sketches to shop drawings.

BTW-kudos to Shawn P for his well reasoned and articulate responses!

[Stewie Simpson]

With the ever increasing reliance on overseas manufacturers such as China and India, and other 3rd world nations to supply our goods and services; whether we like it or not, they will have a controlling influence on the future availabilty of the imperial measurement. IMO

[Derek Cohen]

I think one has to be conversant with both systems of measurement. This is especially so if you use vintage handtools (of any origin) or tools made in the USA. I also tend to purchase Imperial sizes, such as a recent purchase of forstner bits (which I could get through Lee Valley but not in Oz, where these are available only in Metric). The reason for Imperial bits is to "fit" with my Imperial blades (e.g. chisels and plough plane), where they may be used together. Ironically, most screws and bolts sold in Australia are Imperial! Go figger.

One might argue that the notion of Imperial sizing for blades (especially chisels) is not relevant. However it is when one "slaves" tools and the common denominator is Imperial.

I grew up with both systems. Metric arrived when I was 10 years old. Metric was certainly easier to use at school (anyone who has ever had to calculate Pounds, Shillings and Pence would understand this). However, when it came to practical tasks, such as measuring with a tape or rule, both systems had a special place for me, and this continues to the present.

The advantage of Imperial is when measuring longer lengths. It is easier to visualise 12" than 30mm. Actually, that is not too hard. What about 27" versus 685mm? At this distance, Metric becomes overwhelming. By contrast, when small dimensions are needed, it is much easier to see 4mm than a heavy 5/32". And then when it comes to dividing inches, especially those that include a fraction, well good luck - I'd rather use Metric.

So what happens is that I use the two systems side-by-side. My drawings and scribblings mix Imperial and Metric freely at the same time. Once one gets going in a build, however, it is irrelevant since I do not use measurements to mark dimensions, but story sticks.

Regards from Perth

Derek

[Kees Heiden]

68.5 cm, what's overwhelming about that?

A funny story about this issue. I was on a skiing trip in the Canadian backcountry one winter. I have a digital altimeter and had to set it to feet, instead of meters. All went well and on return to Holland I of course didn't use the altimeter (Holland is flat as a pancake) and forgot about it. Next summer we went to the Alps and I found that the altimeter was still set in feet. And of course I couldn't remember the magic button sequence to set the units. This was before the days of easy internet acces, so I had to go to a nearby town into a sport shop who sold the same brand and ask for help.

[Stewie Simpson]

This will cheer you up Kees.

https://www.youtube.com/watch?v=_ZI_aEalijE

[Kees Heiden]

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[Trevor Goodwin]

Here in Australia just about every tool/accessory you buy is in metric, even when imperial makes more sense. Sanding belts, for instance, are given in stupid measurements like 75 x 533mm, when really its exactly 3" x 21". They often ignore the first decimal place, so a 1/2" chisel, rebadged in metric, is either 12mm or 13mm when really it is halfway between.

[William Adams]

Agree w/ Derek, but have a solution to needing to divide smaller lengths — as I noted in my previous response, get a DTP point/pica ruler which uses 1/72 inch points — it’s finer and more accurate than millimeters, and perfectly lines up w/ inches.

Above all, it avoids some of the crazy fractional metrics units which I see at work when metric page layouts come in w/ three and five or six column layouts (even simple two column layouts can have bizarre values for the gutter), and as Trevor noted, discarding a fraction of a millimeter is the difference between being half half correct (it should actually be 12.75mm, right?) or no.

[Curt Harms]

Here in Australia just about every tool/accessory you buy is in metric, even when imperial makes more sense. Sanding belts, for instance, are given in stupid measurements like 75 x 533mm, when really its exactly 3" x 21". They often ignore the first decimal place, so a 1/2" chisel, rebadged in metric, is either 12mm or 13mm when really it is halfway between.

Sort of like "3/4" inch plywood which is really 18mm? It's certainly easier to manipulate number in metric than fractions but with materials, fasteners and tools predominantly imperial here is the U.S. working in metric has its challenges.

[Trevor Goodwin]

Sort of like "3/4" inch plywood which is really 18mm? It's certainly easier to manipulate number in metric than fractions but with materials, fasteners and tools predominantly imperial here is the U.S. working in metric has its challenges.

I've seen various 3/4" tools and materials labelled 18, 19, and 20mm. It is really close to 19mm but I guess some people prefer the look of even numbers.

[Pat Barry]

It makes no difference in the process or result which measurement system you use.

[glenn bradley]

Wow, I didn't know people were so passionate about this. I was raised with both and can use either. It is certainly easier to state 12mm as being the next step up from 11mm than to say that 15/32" is the next step up from 7/16" (or whatever the granularity). I have worked, thought and dreamed in binary, octal, decimal and hex for over 30 years. I stick to imperial in the shop because it seems to relax me. Maybe it uses a different part of the brain .

[Warren Mickley]

The metric system was developed for chemistry, physics, astronomy; inches and feet were developed for woodworking. A foot divides very neatly into halves, thirds, fourths, sixths, eighths and twelfths. One inch makes a nice standard thickness for a board; one foot a nice standard width. Much more convenient. Frankly if we did not have ten fingers no one would have ever picked base ten for a system. Many historical systems use twelve despite the fact that you couldn't count it on your fingers. Older incheswere divided into lines, twelfths, for easy division into thirds.

This reminds me of a little story. My neighbor's daughter broke her leg and the doctor told him he put a 30 cm rod in her bone. The neighbor said "I'm a carpenter can you put that in inches."
Doctor:"It's about a yard"
Carpenter: A yard! It can't be that long."
Doctor:" She has really long legs."

That evening the carpenter took out a yardstick and held it against his leg before calling me up.

[lowell holmes]

I've gone almost totally metric in the last year, my most trusted tape measure has both systems. I've found it easier to divide metric numbers and a millimeter is more accurate than 1/16". Much easier to figure proportions/dimensions when converting preliminary sketches to shop drawings.

BTW-kudos to Shawn P for his well reasoned and articulate responses!

Are your drill augers and chisels imperial or metric.

I know without looking that there are 25.4mm in an inch, but I see no reason to go metric when my lumber and tools are imperial.
I will not go metric just to be clever.

[Rob Luter]

I use Imperial, but do everything in decimal inches. Working as an Engineer for the last 35 years, I've managed to commit all the decimal equivalents to memory. The math is much easier to do in your head.