In industry, we have. At home, most households have little or no use for US dimension tools such as wrenches. You can service a bike with all metric tools.

"Going metric" raises the question of whether we adopt metric measures for our existing standards (such as pipe threads) or actually adopt the ISO sizes. The latter would cause a brief but massive inventory management problem, that nobody's ever willing to put up with, even if there's a long term benefit.

I believe we made a mistake in how we tried to teach the metric system. I learned in first grade: Metric is easy because it's just math. Most people heard "math" and freaked out. Metric was taught as a bunch of conversions and units. Inches were taught as: Here's a ruler, go measure some things.

I remember talking to a machinist, and he said: "I hate the metric system because there's so much math." That was 30+ years ago. Today, machinists just read mm or inches from the same digital readout or CAD program.

My Canadian friends learned metric as: Here's a ruler, go measure some things.

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perilunar an hour ago | parent | next [-]

> "Going metric" raises the question of whether we adopt metric measures for our existing standards (such as pipe threads) or actually adopt the ISO sizes.

You adopt ISO sizes FFS. They are international standards. You really want to invent a whole new set of incompatible 'standards'?

You think the US is the first to go through this? Australia, Canada, and the UK went metric in the 1970s (we also decimalised our currencies). Yes it was challenging for some adults but mostly pretty easy for kids. People adapted. Industries adapted. Now we hardly think about it except when dealing with Americans or in some historical contexts.

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SoftTalker an hour ago | parent [-]

For the piping example, you have all the installed infrastructure that's in the old "IPS" (straight) and "NPT" (tapered) sizes. So now a plumber needs to carry additional fittings or carry conversion fittings. Easier to just stay with what we have.

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perilunar an hour ago | parent [-]

Of course it's easier to stick with what you have in the short term. Change is difficult. You do it for the long term gain. If you had done it 50 years ago like the rest of the English-speaking world you wouldn't be in this mess.

	▲	SoftTalker an hour ago \| parent [-]
		What's the long term gain? It's just a unit of measure, ultimately arbitrary. Standards bring efficiency, and we already have a standard.

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SoftTalker an hour ago | parent | prev [-]

Imperial measurements do have the benefit of more even divisors than metric.

Pretty common to talk about measurements of 1/2, 1/4, 1/8, 1/16 of an inch and find those graduated on a ruler. Or 1/2, 1/3, 1/4, 1/8 of a cup for liquid measures, etc.

But then machinists generally work in thousandth or ten-thousandths of an inch.

	▲	analog31 9 minutes ago \| parent [-]
		I'm a fairly experienced machinist, though it's not my occupation. At the present time, machinists have the least problem with metric. The unit conversions are built into all of the machines and measuring tools. You press the inch / mm button. The ruler has inches on one side and mm on the other. Everything is standardized on IEEE floating point. ;-) It's a headache to maintain collections of parts and tools such as taps and dies for both standards. The biggest shift is simply the obsolescence of old stuff, and emergence of new stuff. And industries have adopted the practice of reducing the overall variety of parts needed. I work in the development of industrial measurement equipment, and where a design might once have had 30 different sizes of fasteners, now it's 5, all metric. Designs rarely need nuts and spacers any more. Washers are integrated into the screws. No more "philips" or flat head screws. And so forth.