Respectfully, Chronos, as a former machinist helper (and proud Union member), I can truthfully state that I have never heard a Vernier caliper called a micrometer. We used a caliper (or calipers) for rough measurements only.
So what is the general name for that instrument, then? It’s not a Vernier, because that’s specifically for that type of readout (which, admittedly, is seldom used for anything else, but not all such instruments use one).
Vernier caliper.
But the old guard will often call it a vernier.
And I had to really concentrate to read that metric micrometer, not that the imperial ones are better, but it’s certainly something that gets easier with familiarity.
As much as I love the elegant mechanical simplicity of the Vernier scale on calipers and micrometers, life is too short to be squinting to read one of those. So I use those Mitutoyo micrometers that have a little mechanical odometer mechanism. And dial calipers.
Back more to the OP.
TVs are not the problem. Computer monitors are a disaster, as there are so many aspect ratios. One can get ultrawide gaming monitors that are basically a 4k monitor sliced across the middle making a 32:9 aspect ratio.
The other weird size is that used for camera sensors. Here many sensors are defined as the diameter, in inches, of a vidicon tube that would hold that sensor. The glass tube typically being 50% larger than the diagonal of the sensor. So a micro 4/3rds sensor is 4/3 x 2/3 = 8/9 = 22.6mm diagonal, yielding a die size of 18 mm × 13.5 mm. The actual sensitive area is less again: 17.3 mm × 13.0 mm for a diagonal of 21.63 mm. Which is a lot less than the 33.9mm 4/3rds of an inch might suggest.
Other small camera sensor sizes are similar. At the big end, full frame just matches the old 24x36mm image size of 35mm film. What they currently call medium format is mostly smaller than the 56mm wide image on 6cm wide film (aka 2 1/4 inch) at 43.8 x 32.8 mm. Not unless you have serious money laying around for a 53.4 x 40 mm sensor that nearly matches the old 645 format.
It’s 1219 x 2438mm. If you round the numbers the way you suggest it’ll be a full 1 1/2" short over the length of a panel, which is the width of a stud. That’s a problem if you’re trying to line up panels based on standard framing spacing (16") unless you also adjust framing spacing to 400mm (15 3/4").
51 x 102mm but I’d say that’s close enough. However, that’s not how big a 2x4 is, it’s 38 x 89mm or 1 1/2" x 3 1/2". It’s like how a Quarter Pounder is based on the pre-cooked weight of the burger patty. Dimensional lumber is the pre-trimmed or pre-rectified nominal size. They effectively shave 1/4" off each side to square it up (3/8" off sides 8" and up). Manufactured woods like LVL’s, PSL’s, LSL’s, glu-lams, plywood, OSB, or i-joists are sized to be compatible with standard dimensional lumber, but their actual sizes are called out because they don’t have nominal sizes. For example, you don’t specify an 8" LVL beam to fit in 2x8 framing, you specify a 7 1/4" LVL. That’s also because they may have multiple sizes that would fit under the nominal umbrella, such as 9 1/4" and 9 1/2" or 11 1/4" and 11 7/8" (specifically I think the odd sizes are for compatibility with i-joists, but the 11 7/8" LVL gives you a decent bit of extra structural oomph).
Yes, of course. Mil is more common. My retirement brain is turning to jelly.
Funny no one has mentioned smoots. A smoot is 5’7".
A lot of the confusing measurements are hold-overs from imperial days. Yes, you can buy food and drinks in ml but a can of soda will be 284ml (10oz) and a bottle 710ml (26oz?) to match US bottle sizes presumably to simplify bottling equipment. Whereas you can buy 1L and 2L larger sizes (Even in the USA IIRC) because the equipment and expected serving is new since metrification and was not matching a standard size from previous. (IIRC the biggest old glass bottles were 40oz.) OTOH, milk, which is entirely local, long ago switched to metric - 1L, 2L, 4L - which roughly mirror the previously expected 1Q 2Q 1Gal sizes.
Houses have an even longer life, so switching lumber sizes would be a nightmare, particularly when a 10x larger market south of is is not changing. Yards would ahve to stock inches and feet fot repairing old buildings and then metric for new, not to mention all the other associated pieces like shingles, pipes and ventilation, windows, etc.
(I’m reminded of that scene in Brazil where the secret police go to put a cover on a hole they cut in the floor, and it falls straight through. “Bloody hell! They’ve gone back to metric without telling us!”)
Because it’s a joke unit made up by privileged frat boys.
For what it’s worth, I’ve always called it a micrometer and Google image searching the term “micrometer” actually shows the calipers first. But the description mentions “caliper.” I’m not a tradesperson, though. Just a schmoe
who works around the house sometimes and has one of those. I must have picked up the usage from someone else, though, come to think of it, my dad was a tool and die maker and he called it a micrometer (but my dad’s first language isn’t English and I suppose it could have been a conflation between the two types of measuring tools.)
Hmmm…not on my Google. Of course, terminology may vary, but I would have had a stern lecture from my machinists if I brought them calipers when they asked for a micrometer.
I’m not biased against calipers. I’m sitting on my couch in the den and I have two calipers handy. One is in my end table and one is on the coffee table in my pen jar. I use them a couple times a week to measure everything from my wife’s beads to screws I need to replace. But my micrometers are back in the craft room.
Hold-overs for sure, but I thought U.S. bottle sizes were deliberately not imperial, hence phenomena like the 355 ml drink can vs the 341 ml can. That is, the old bottles did not match the US versions anyway. Wikipedia says some US sizes were introduced in Canada with newer (1980s and 1990s) aluminium can equipment .
One of the biggest problems with the “customary system” is that it’s not a system; it’s a whole bunch of different systems. As evidenced by the number of people who refer to the American system as “imperial”. The imperial system and the American system are two different systems that just use mostly the same names.
As illustrated by this paragraph from Wikipedia:
The American colonists adopted a system based on the 231-cubic-inch wine gallon for all fluid purposes. This became the US fluid gallon. Both the imperial and US fluid gallon are divided into 4 quarts, 8 pints or 32 gills However, whereas the US gill is divided into four US fluid ounces, the imperial gill is divided into five imperial fluid ounces. So whilst the imperial gallon, quart, pint and gill are about 20% larger than are their US fluid measure counterparts, the fluid ounce is about 4% smaller
Metric plywood here in the UK is 2440 x 1220, which is a millimetre or two larger than the old 8x4
So the whole US system is based on wine merchants who customarily shorted their customers on the size of a gallon?
Chronos argues that it is not a system, but after reading your post I think it is more of a system than Chronos thought. It pervades the whole culture! Why this does not go all the way down to the fluid ounce is a mystery. Shots of whisky are too cheap, mugs of beer too expensive.
But it seems the 2 by 4 has changed repeatedly and substantially in the last 100 years, which does not seem to worry the yards you mention. Should be called meters anyway.
It’s certainly less of a system than metric/SI, whose units have been intentionally designed in such a way that units for different quantities can easily be converted into each other. If, for instance, you want to calculate the gravitational attraction between two bodies using the F = G * m1 * m2 / r formula, and you’re plugging in each quantity measured in its usual SI unit (kg for mass, metres for distance etc.), the result will be in the relevant SI unit (Newton), without having to worry about conversion.
That only goes so far. Otherwise there would be no magic numbers, i.e. you would just have G=1.
I have personally run into the problem of trying to replace an old “2x4” with a new “2x4” and finding that they weren’t the same size. The mill lobby doesn’t give two cents about compatibility with your (slightly) older house.