Tilton RaccoonMan, I thought US lumber sizes were fucking weird, literally EVERY TRADE is fucking weird here. I need NM wire clamps for our main electric service box. The punch-out hole measures 7/8" in diameter (22.5mm). The trade calls this a 1/2" punch-out, but you don't buy a 1/2" clamp, you buy a 3/8" clamp. So yes, you need a 3/8" clamp for a 1/2" hole that actually measures 7/8". Thanks, I hate it.
Charlie Stross@tilton @a_cubed And inches are 25.4mm give or take a few microns! I mean, who ordered THAT? It's almost as crazy as the pre-revolutionary French Foot, which was the distance from the tip of the king's nose to the end of his right middle fingertip (arm extended stiffly from the shoulder) because why the fuck not (and also, it varied from king to king).
Jeff@cstross @tilton @a_cubed NIST ordered it, and there's no give or take. A US inch is exactly 25.4mm to as much precision as your equipment allows. That is the official definition, and why I like to call US customary units The Worst Version of the Metric System. NIST redefined everything in terms of metric units half a century ago.
@overeducatedredneck @tilton @a_cubed Oh good grief. That's as bad as the British Metric Pint (568ml precisely, legal/statutory measure for serving beer in pubs, used for NOTHING else.)
Nick Taylor@cstross The UK has also been on the metric inch since like the 1930s. Saved our bacon in WWII because American-machined parts *weren't* a few thou per inch out.
Of course, in practice both the US and the UK had been on the metric inch for a while before then because the (I think Swedish) chap making the gauge blocks got fed up with having to maintain two product lines and split the difference between the two inches.
Cadbury MooseIt's worse than that. The UK Arms industry (RSAF Enfield) used their own "Enfield Inch" standard from the 1850s for measurements under 2 inches, and the "Imperial Inch" (0.0004" larger) above that size. The "Metric Inch" was much later (1930) and 0.0000017" longer than the "Imperial Inch" or 0.000002" shorter than the US one. It caused problems with gun manufacture during WW2 in that US and UK parts weren't interchangeable. A more recent difficulty was the licensing of... 1/
...the Pattern 1853 Enfield Rifle to an American company for reproduction/reenactment purposes. The UK manufacturer supplied the drawings, dies, and various gauges, plus an original rifle as a pattern/test piece, and the US company set to work. They then complained that their parts would not interchange with the original rifle, despite precisely matching the drawings... "Are you using the Enfield Inch?" was the reply "We sent you a standard". "Er, what?" "Oh crap." ... 2/
...explanation followed: "There's a small wood box with sliding top and a gauge block inside it marked Enfield Inch; that's the unit used in all the drawings."
"Oh." they said, and retooled for the smaller "Inch".
Problem solved.
I remember being horrified by the "Bushel" and "Barrel" measures being different according to the item being measured - the old "Mathematical Tables" books had a reference section on the back page for some of them.
The old units linger on...
UK Beer is still sold in "Pints" - a somewhat arbitrary measure in some places - Shipping containers use the "TEU" (Twenty-Foot Equivalent Unit) for size, Steel drums are 200 litre, 55 (U.S) or 44 (UK) gallon capacity - and they're all the same size, and so on. At least we've ditched Apothecaries Measure and (nearly) everything except gold is measured in grams & kilograms these days. 4/last. 3:O))>
@Cadbury_Moose @tienelle This incidentally is why American cooking recipes are useless—they use volume as a measurement for solids! Not weight. So in what universe is a "cup" of lead shot the same quantity as a "cup" of popcorn?
"Mediocre Bunny" Evelyn@cstross @tienelle @Cadbury_Moose
If you’re putting a cup of lead shot and a cup of popcorn into the same recipe, I’m not sure I want to know what you’re cooking.
If you’re putting a cup of lead shot and a cup of popcorn into the same recipe, I’m not sure I want to know what you’re cooking.