5 ms·

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 a

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

nickpinkston 4y ago
I had an old machinist ruler that actually did have 64ths - barely could read it haha - time to get out the calipers! 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.
bittercynic 4y ago
I don't think it's usual to make that jump, but to use fractions in some contexts, and thou in others. Around a machine shop the measuring devices go by decimals, and in wood shops they use fractional measures.
rtkwe 4y ago
It mostly stops around 32nds to at most 64ths at best in woodworking where it gets hard to measure accurately using a tape and the Mark 1 Human Eye. Then in machining there's usually digital or dial readouts for things so it's easier to work in a round number like 1000s.
tedunangst 4y ago
"instead of our engineers and machinists thinking in eighths, sixteenths and thirty-seconds of an inch, it is desirable that they should think and speak in tenths, hundredths, and thousandths"
Jedd 4y ago
Yeah, it's a bit of weird disjoint. Almost a tacit admission, in fact. 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.
- BeFlatXIII 4y ago
  How do they measure out ⅓ and 1/6 and 1/12 using only base 10?
  - AndrewDucker 4y ago
    Here's the trick: They just don't do that.
  - zokier 4y ago
    Same way as you'd measure 1/7, 1/11 etc.
  - nautilius 4y ago
    “Only base 10” is already the measure of choice where it matters most for most Americans: gas, money, ammunition. It works just fine.
kazinator 4y ago
No, it's because the mil works with decimal fractions. 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.
kazinator 4y ago
Mils are awesome for wire thicknesses, trace widths, pin spacings on circuit boards, fine drill bit sizes for through holes ... 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.
- Jedd 4y ago
  > The metric system doesn't have a nice mil-like unit for those scales; the millimetre is way too crude, and micrometres are too fine. 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.
  - kazinator 4y ago
    That 0.046" is just called 46 mils though, or just 46 when that is understood. Those guitar strings are just "nine to forty-sixes" and that's it. 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.
- guenthert 4y ago
  > 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. 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'...
ranger207 4y ago
My guess would be that fractions with a powers-of-2 denominator were used in pre- and early-industrial contexts and remain in use today by long tradition, but thousandths started to be used only later in industrialization when the benefits of a base 10 system were more clear

nickpinkston 4y ago

I had an old machinist ruler that actually did have 64ths - barely could read it haha - time to get out the calipers! 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.

bittercynic 4y ago

I don't think it's usual to make that jump, but to use fractions in some contexts, and thou in others. Around a machine shop the measuring devices go by decimals, and in wood shops they use fractional measures.

rtkwe 4y ago

It mostly stops around 32nds to at most 64ths at best in woodworking where it gets hard to measure accurately using a tape and the Mark 1 Human Eye. Then in machining there's usually digital or dial readouts for things so it's easier to work in a round number like 1000s.

tedunangst 4y ago

"instead of our engineers and machinists thinking in eighths, sixteenths and thirty-seconds of an inch, it is desirable that they should think and speak in tenths, hundredths, and thousandths"

Jedd 4y ago

Yeah, it's a bit of weird disjoint. Almost a tacit admission, in fact. 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.

BeFlatXIII 4y ago
How do they measure out ⅓ and 1/6 and 1/12 using only base 10?
- AndrewDucker 4y ago
  Here's the trick: They just don't do that.
- zokier 4y ago
  Same way as you'd measure 1/7, 1/11 etc.
- nautilius 4y ago
  “Only base 10” is already the measure of choice where it matters most for most Americans: gas, money, ammunition. It works just fine.

kazinator 4y ago

No, it's because the mil works with decimal fractions. 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.

kazinator 4y ago

Mils are awesome for wire thicknesses, trace widths, pin spacings on circuit boards, fine drill bit sizes for through holes ... 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.

Jedd 4y ago
> The metric system doesn't have a nice mil-like unit for those scales; the millimetre is way too crude, and micrometres are too fine. 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.
- kazinator 4y ago
  That 0.046" is just called 46 mils though, or just 46 when that is understood. Those guitar strings are just "nine to forty-sixes" and that's it. 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.
guenthert 4y ago
> 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. 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'...

ranger207 4y ago

My guess would be that fractions with a powers-of-2 denominator were used in pre- and early-industrial contexts and remain in use today by long tradition, but thousandths started to be used only later in industrialization when the benefits of a base 10 system were more clear