Imperial or Metric?

[Yonak Hawkins]

For someone just starting out I think the metric versions of tools such as router bits and drill bits are going to be harder to find, less options, and more expensive than their American counterparts. I looked up drill bits at home depot website and you get an equivalent set of metric and American but the metric set has only about half as many sizes and it costs a bit more so the cost per bit is about 2.2x the cost of the American bits. I took a quick look at Rockler and from what I see they don't even sell metric router bits.

I believe this is a matter of good business tactics to offer what the customer wants. However in a broader sense, an increasingly globalized world, as Dennis says, can't continue to use different methods of measurement, no matter what method is adopted. Business will eventually choose the most cost efficient path and the general population will slowly and begrudgingly adapt.

[David L Morse]

I find it interesting that metric sizes are used for the retail packaging of water, wine and spirits while beer is sold in imperial units.

[Halgeir Wold]

Do you need a metric hammer to pound your glue-ups into submission if you build something using metric measurements?

Yes you do - because a 4'' hammer is just too large to hit a 100mm something.. :-)

The light definition was based on comparing with the meter prototype, to the nearest fit, at an exact temperature and humidity.
Before todays definition there was another one also based on light, but a much more quirky one of light from krypton atoms at a certain energy excitation state,- 1 650 753.73 wavelengths of them, to be exact.....

[Jim Stearns]

Here's a good one I stumbled across recently. I bought a hardware assortment from Menard's. In it there were 1/4", 5/16" and 3/8" bolts, nuts, etc. Also some smaller #6, 8 etc. Chinese of course.
The thing is, the 1/4" bolts had 10mm heads instead of 7/16" like normal for imperial bolts. So 1/4" bolts with metric heads. I never saw that before.

Tonight I encountered it again. I just bought a Grizzly band saw. While assembling the stand I found the same thing; 1/4" bolts with 10mm heads.

[Charles Ratz]

For those that have switched to metric, how do you get used to "estimating" in metric? For example, I can picture a board that's three feet long, but not 1.5 meters. I have to convert in my head from a meter to about 40 inches x 1.5 = 60 inches or so. Liters aren't bad since it's about a quart but kilograms? Hard to do in your head.

Is it just a matter of practice and struggling until you have a feel for metric dimensions etc.?

[John Coloccia]

For those that have switched to metric, how do you get used to "estimating" in metric? For example, I can picture a board that's three feet long, but not 1.5 meters. I have to convert in my head from a meter to about 40 inches x 1.5 = 60 inches or so. Liters aren't bad since it's about a quart but kilograms? Hard to do in your head.

Is it just a matter of practice and struggling until you have a feel for metric dimensions etc.?

I use decameters, which is about 4" long. I never actually SAY decimeters, but I can reliably judge 4" (1dm..10cm), 6" (1.5 dm or 15cm) and 12" (30cm or 3dm). It's not exact, of course, but it's close enough to work with.

[Rod Sheridan]

For those that have switched to metric, how do you get used to "estimating" in metric? For example, I can picture a board that's three feet long, but not 1.5 meters. I have to convert in my head from a meter to about 40 inches x 1.5 = 60 inches or so. Liters aren't bad since it's about a quart but kilograms? Hard to do in your head.

Is it just a matter of practice and struggling until you have a feel for metric dimensions etc.?

Charles, you never had a built in ability to estimate things in Imperial, you learned by experience.

Same with the metric system, start using it and you'll become familiar............Rod.

[Chris Padilla]

Celsius or Fahrenheit? Or perhaps you might prefer kelvin?

[Chris Parks]

To be truthful and keep in mind I converted years ago some things for some people never quite "Gel". It is the generation that follows that never used any other method that truly gets it. I for instance have one big issue and that is the height of people. If someone asks me how tall I am I haven't a clue in metric. It is a bit like someone asking for your mobile phone number, most don't know it because they never have to quote it. If the police asked me for the height of someone I would have to quote it in imperial which given all the coppers have grown up with metric would be really funny. It seems all those who convert have isolated problems of this nature, my wife has never converted to measuring in metric but is fully conversant with weights etc through buying groceries.

[Rod Sheridan]

Celsius or Fahrenheit? Or perhaps you might prefer kelvin?

The numbers in Kelvin and Farhreneit are too large for my simple brain.................Rod.

[dennis davidson]

Why not use a set of dividers, almost no measuring required and absolutely equal divisions.

[Curt Harms]

For those that have switched to metric, how do you get used to "estimating" in metric? For example, I can picture a board that's three feet long, but not 1.5 meters. I have to convert in my head from a meter to about 40 inches x 1.5 = 60 inches or so. Liters aren't bad since it's about a quart but kilograms? Hard to do in your head.

Is it just a matter of practice and struggling until you have a feel for metric dimensions etc.?

A meter's a 'long' yard - about 3' 3"

A millimeter is about halfway between 1/16" and 1/32", actually 1/25.4"

6mm ~ 1/4"
8mm ~ 5/16
10mm ~ 3/8
13mm ~ 1/2"

A kilometer is a little over 1/2 mile, about 5/8.

Remember this is about 'estimating'

[Shawn Pixley]

I want to use AU's in scientific notation just to be different.

[Mark Woodmark]

I agree metric seems easier to work with. As for working with fractions, I have memorized the decimal equivalents to the fractions through 32nds and some 64ths. This makes figuring with a calculator easy. For any odd fractions, I divide the top number by the bottom number to get the decimal equivalent. This is somewhat cumbersome and I round the decimal to 5 places in most cases. I find this to be accurate enough for most cases.

[Keith Weber]

I round the decimal to 5 places in most cases. I find this to be accurate enough for most cases.

5 decimal places? 1/100,000th of an inch is accurate enough for MOST cases??? What exactly isn't falling into the "most cases" category in your shop? I'd love to see the equipment you're using that comes anywhere close to those tolerances or accuracy. I'm picturing 20-ton machines in a temperature-controlled lab where you can't touch the materials that you're working on with your hands.