Also skin (for tannery) is measured in square foots, or it was twenty years ago. Perhaps UK controls the commerce here too?

It’s like the Australian farm woman who complained that her hens were laying smaller eggs ever since the country adopted the metric system.

Michael Duff mentioned the case of a woman who was asked by a TV interviewer if she believes in Global Warming. She said: ”If you ask me, it’s all this changing from Fahrenheit to Centigrade that’s causing it”.

Then there is the triplets of tonne (metric tonne), short ton and the long ton.

Wonder whether the short ton (2,000 lbs) is an American invention that attempts to maintain a semblance of going Metric!

And then there is Shimano, who produces bicycle parts that don’t conform to anyone’s unit system and for which one needs a new tool each time there is a new line of parts!

Some here might be amused at space mission teleconferences during the mission’s instrument construction and integration phase, if those missions involve instruments and spacecraft built in different countries. There are detailed discussions of nuts, bolts, screws and their tools. Sometimes these screws and tools items are given to the other teams (with the appropriate paperwork and if it doesn’t involve ITAR).

One good example of task specificity came up in the IEEE magazine. Why are capacitors denominated in microfarads and picofarads, but never in nanofarads? Obviously, microfarad range electronics designers work in microfarads, while picofarad range designers work with picofarads. Need a nanofarad, use a 1,000 picofarad capacitor.

As a fish egg fancier, I always wondered why did the godless (and metric) Soviet Union sold caviar in 14 ounce pounds? Their system of pressure altitudes for high flying aircraft is metric, but different from the Chinese metric pressure altitudes. Of course, low flying planes, up to 18,000 feet measure altitude based on calibrating the altimeter at takeoff using barometric pressure and known elevation, so the aircraft altitude approximates actual altitude over mean sea level. Go over 18,000 feet and its all done with millibars, and calibration be damned. So if you are flying in a small plane and your pilot says you are at 4,000 feet, those feet are not the same as the feet a jet pilot would use when announcing that the plane is at 32,000 feet.

Also, when was the last time you bought produce or meat by the ounce? My supermarket, and just about every other supermarket in these United States, sells by the pound and the hundredth. In other words, the supermarket checkout station designers have imposed a decimal based system on us, and since it was done by a business, not the government, there has been nary a squawk. Try finding a 32 fluid ounce bottle of Coke or 4/5 gallon of Scotch. It’s like gasoline, sold by the gallon and the hundredth.

Designing parts is a lot of hassle. Translating inches to mm and back for every part, hoping that something doesn’t get messed up. Most people have no idea whether 9/64 is greater or lesser than 3/16. They might have some idea what 0.14 is compared to 0.18, though. To compound these problems, most americans are terrible with fractions. I mean, the 1/3 pound burger didn’t survive simply because most people thought it was smaller than quarter-pounder!!!

Ever tried to find the correct allen wrench for a screw? Slightly smaller… Nope, slightly bigger… Maybe it’s metric? Is this metric or is this english? Two sets of wrenches for everything… buying screws just to find they are the wrong size…
A lot of machine parts are made in germany and japan… guess what system they use? etc. etc. Absolute nightmare.

Mr. Machine Shop guy, here’s the drawing - this M5 screw should be 1/4″ from one edge and 78.3 mm from another edge. Use calculator if you want to double check the numbers.

When US Marine Corps started changing their mannuals to fit the metrical sistem, they simply expressed it “1.000 meters from the beach” (you know… a meter and a yard are so near, and a beach is never “straight lined”, so…)

But it’s not true that everything was measured into convenient “dozens or scores” of units. For instance, portable weapons were defined into inches/100 (.30 in rifles, and so on…)

The big problems I see are: 1 - changing all industrial standards (used for centuries, now) to metric system, when the main producers of it are used to Avoirdupois measures; 2 - People around the world are so accostumed to use Avoidupois units, followed by the metric expression (for instance: .30 caliber - 7,62mm; 1″ pipes - 2,56 cm) that it will not change an inch (2,56 cm) in anything…