Curious why we jump from 16ths or 32ths to thous rather than 64ths, 128ths, 256ths, 512ths and 1024ths
I guess they are a mouthful without good abbreviations and there was a tech jump between woodworking and machining so in betweens aren't used
I guess they are a mouthful without good abbreviations and there was a tech jump between woodworking and machining so in betweens aren't used
I've heard that in some crazy parts of the world - say 95% of the planet - it's base-10 all the way down.
Makes you wonder if they're on to something with that kind of whacky scheme. Hopefully it works out for them.
Guitar strings are, e.g. 9 to 46: .009" high E, .046" low E.
Classic DIP (dual in-line package) integrated circuits and headers have 100 mil spacing: ten pins per inch. IIRC, you drill a 25 mil hole for the pins. This is international.
The metric system doesn't have a nice mil-like unit for those scales; the millimeter is way too crude, and micrometers are too fine.
The mil is just right for all sorts of miniature things that are still large enough to be worked on by human hands and eyes.
This kind of absurd claim would be more compelling if you hadn't just used 3 decimal places and a quotation mark to define a distance in a format used by at most ~5% of all the people working in such scales:
> ... 0.046"
My point - metric can also use decimals. More adroitly, too, I'd argue, because of the consistency.
If you're routing a circuit board, you have a grid that is a multiple of the mil: e.g. 25 mils, so if have a part with 100 mil pin spacing, that is four grid lines. Trace widths are multiples of a mil: 6 mil, 8 mil, ... through holes are mils: 25 mil, 40 mil, ... no decimal point or " mark in sight.
Sure, a tenth of a mm would be a useful unit. Problem is, 0.1 mm has no name. It's either 0.1 mm or 100 microns, which are too small. I've not seen anyone define such a unit in practice; they just plod along with multiples of 0.1.
But that's just a historic accident.
Related, the metric system was forced upon trade in Germany not before the early seventies. Only few units previously used survived, e.g. the 'Pfund' (pound, now redefined as 'half kg'). My father continued to use 'Zoll' (inch) and lamented American made machinery using threads on nuts which differed from those used in Germany (and everywhere else). Even I know the folding carpenter's ruler only as 'Zollstock' (no one says 'Gliedermaßstab').
And while I used to be very opinionated about the imperial- vs. metric system, after twenty years in California, I feel comfortable at 75°Fahrenheit and am exhausted, if I have to walk more than a few miles. I even caught myself recently referring to a width as 'about a yard'...
One reason these whole even numbers are used is because it's easier to inspect with basic tools - ie just fold/layer it a few times and measure the thickness - like using a rule to measure 64 sheets of 1/64" stock and hoping to get 1". The evenness is about doubling/dividing to achieve this effect.
They also had very primitive measures for bore size that worked the same - ie "gauge" for shotguns was the number of how many balls of the barrel's size added up to 1 pound of lead, so you could have a basic scale and infer everything from there.
If a measurement is 3.125 inches, you know that it's 3 inches and 125 mils.
You don't need support for fractional syntax in order to have an input field for inches that goes down to mil precision: just a regular decimal numeric input.
You cannot dismiss the advantage of decimal fractions as casually as you can reject the metric system.