Machinist's Minute: Irrational (metric) numbers

Рет қаралды 21,125

HOWEESMACHINESHOP

Күн бұрын

We can have a rational discussion about this.

Пікірлер: 179

@Phantom-mk4kp 2 ай бұрын

The craziest thing is a car tyre that has an imperial diameter and a metric width and a percentage profile

@arnearne12345 2 ай бұрын

the crazier thing is that the inch has been defined by the meter for decades

@beefchicken 2 ай бұрын

Maybe tire sizing was invented by Canadians? Everything we do is a mixup of units.

@beefchicken 2 ай бұрын

@@arnearne12345the change of the inch from the pre-metric definition resulted in a 2 ppm change in the length of the inch. The redefinition of the meter from its original geocentric definition resulted in a change of 247 ppm in length. Even factoring in the differing unit sizes, the meter still changed by 6 ppm vs. 2 ppm for the inch. It looks like the inch is more stable over time to me… (metric lovers: I am joking, please do not get all up in my grill)

@Phantom-mk4kp 2 ай бұрын

@@beefchicken The standard definition for 1 metre since 1983 is the distance covered by a laser beam inside a vacuum over a defined time. Unfortunately the chaps, dudes(choose accordingly) who's tasked with calibrating the tape measure never exit the vacuum chamber. Perhaps there's your problem

@arnearne12345 2 ай бұрын

@@beefchicken ppm is a unit for measuring the particle density in a given volume

@1985230ce 2 ай бұрын

I’ve used both systems in a machine shop. I prefer metric. One example is tapping. There is a 3/8-24 thread required. You have to look on a chart to find the tap drill size. If you have m8-1.25 then you subtract 1.25 from 8 and 6.75mm is your tap drill. Clearance hole sizes are easier to figure out too with out looking at a chart especially on number size threads.

@jaydeebishop2345 2 ай бұрын

I was raised on the metric stuff. I discovered the king's thumb as soon as I got on the job. I now use both every day like any CAD technician. To me, 0.0625 is the second best unit of increment. And yeah, 1 is my numder one.

@whitetailtherapy7908 2 ай бұрын

Been in machine shop for over 20 years and man I hate metric lol first thing i do is convert it all over to inches lol

@007oskari Ай бұрын

Makes sense when You're learning it whole life. But if we'd explain both to an Amazon Forrest dudes who measure with fingers, it would be other way around, metric just basically goes from 1-2-3 etc and everything is a round clear number. Even Heights in imperial is ridiculous coming from knowing both, writing 6,1 should be converted exactly as is, meaning it would be 6,1 feet, 61 in the next unit and 610 in the next and 6100 in the next. In metric my height is usually said as 184cm, but I would go from up to down:1,84meters~184centimeters~1840millimeters and so on and so on, that makes math so much more easier if you know both

@The4Crawler 2 ай бұрын

I use both for my work. If machining some part that's metric to begin with, I use metric. If machining some part that's designed in imperial, I use that. My lathe and milling machine dials are imperial, so that's the easiest to use if it make no difference. My biggest issue with metric is in terms of threads on bolts and screws. There are several different standards on what pitch thread on what diameter fastener. So I end up having to stock perhaps 3 different thread pitches of metric hardware vs. only 2 for imperial/SAE (coarse and fine). A lot of my work is with Japanese vehicles and they like to use metric extra fine pitch h/w and since most of the US metric stuff is imported from Europe, it's often only available in coarse and fine. There is one upside of these multiple metric h/w standards. That is, if you own a Japanese and a German vehicle, you can buy one set of metric wrenches/sockets and split them up between the two vehicle tool boxes. I think you only need to double up on the 10mm tools.

@bmacpher 2 ай бұрын

13mm spanners grow legs, in my experience. You can never have enough.

@GimpGladly 2 ай бұрын

Always double, no triple, no quadruple up on 10mm sockets

@edwardhuff4727 2 ай бұрын

I thought for a moment that √(-i) isn't irrational, but actually, you're right. It's the point at (-√2/2,√2/2), or 135° on a radius 1 circle. However, i is rational. It's the point at 90° on a radius 1 circle, or (0,1). Also, √(-2i) is rational. It's the point at (-1,1), or 135° on a circle of radius √2.

@jonludwig8233 2 ай бұрын

i is neither rational nor irrational, it is complex 🤓 you are right about the circle, if you mean a circle in the "complex plane".

@Trayjan00 2 ай бұрын

It doesn't matter what system is used as long as you are accurate and precise with them......everything else is preference.

@miles11we 2 ай бұрын

A lot of people who don't have a handle on the other system get annoyed and justify their laziness by saying one is universally the only one anyone should use ever. 9 times out of 10 they are bitching about it in a situation where the units chosen don't matter in the slightest, it's just the proportions that really matter and it's just like dude, just multiply whatever number you hear by 3 or 10 or 1.5, it doesn't matter.

@Ben-kt5rc 2 ай бұрын

There's no particular advantage to a unit based on the average width of a human thumb or on the distance from the equator to the north pole. For rough and ready working there's some benefit to using fractions. For precision, decimal wins hands down.

@claytondaniel8119 2 ай бұрын

When i started out in cutter grinding one of the older guys would always say a half of a tenth is 50 millionth . This just really helped me put the zeros where they belong. I hate the metic system. I have to convert back to normal numbers when they give me a new drill to grind. The Germans love microns.

@Daniel_en_el_trabajo 2 ай бұрын

china like what you pay

@Phantom-mk4kp 2 ай бұрын

@@claytondaniel8119 cutting a fraction into fraction into a fraction is dumb, a half of a tenth of a thousandth, just say a twenty thousandth

@edwardhuff4727 2 ай бұрын

@@claytondaniel8119 Probably he said half of a tenth is 50 _mils_. A mil is a thousandth, not a millionth.

@claytondaniel7832 2 ай бұрын

@@edwardhuff4727one half of 1/10000 is .00005 or 50 millonths

@claytondaniel7832 2 ай бұрын

@@Phantom-mk4kpin the machining trade a 10th is short for 1/10000ths. If you are not a machinist then you probably did not know.

@CNCMatrix 2 ай бұрын

I use both but metricanese I only use for carbide drills/cheating tap hole sizes, otherwise metric doesn't make sense. They're both units of measurement, they both get you where you need to go.

@creepyloner1979 2 ай бұрын

doing any sort of math involving measurements that end in random fractions instead of simple decimals is just needless extra suffering and frustration. only time i'll use inches is if there's no math involved and i'm just measuring something that was designed using inches.

@beefchicken 2 ай бұрын

What if I told you that you can use inches without fractions? Every machinist has the decimal equivalents for the fractional values memorized. The really good ones can do it down to the 1/64th. And sometimes fractions are easier. Half of 11/32? 11/64. Double 5/16? 5/8. What’s half of .353? What’s two times .797? The interesting thing about the use of fractions is that it constrains designs to quantized portions of units. An imperial part will always have the mounting holes some fractional distance apart. But metric? I’ve seen metric parts where the spacing between mounting holes is completely arbitrary, seemingly random decimals of millimetres. It makes working with them in a design frustrating.

@creepyloner1979 2 ай бұрын

@@beefchicken NOW TRY DIVIDING FRACTIONS BY ANYTHING OTHER THAN TWO, YOU DISHONEST POS.

@benpeterson9835 2 ай бұрын

What if I told him that he could use fractions without inches ? Like 1/2 of a millimeter 🤯 the plot thickens . It’s ALL rational

@Ben-kt5rc 2 ай бұрын

@@beefchicken In my experience, apparently random decimals in metric drawings are typically due to an imperial measurement influencing the design somewhere along the way!

@LysanderSpooner-ie7gg 2 ай бұрын

and yet... the entire world uses inches for socket drive sizes. 1/4, 3/8, 1/2 etc

@scottwhitley3392 2 ай бұрын

I’m from the uk. I use metric while machining but in every speech I use metric. Can pretty much convert instantly between the 2

@christophersines8238 2 ай бұрын

Really it comes down to you preferring base eight or base ten.

@RinkyRoo2021 2 ай бұрын

I can do both but as a kid I really struggled with fractions I like inchs in Machine Shop, but for construction I like Metric My main problem is there's literally 10 different measurement systems with alot of stuff . From wire to rocks there's all these different scales in use.

@swgard1 2 ай бұрын

That square root of 2 can come in handy for checking 45 degree cuts, multiply the width by sqrt2 and you get the length of the face… easy calculator math and quick inspection

@HOWEES 2 ай бұрын

The approximation of the square root of 2 is useful, but the exact number is irrational. This is a mathematics's Joke.

@tas32engineering 2 ай бұрын

Points to remember when selecting lead of machine 1/ It's an advantage and probably necessary to select a position which will factorize with the denominator of gear ratio.

@dans_Learning_Curve 2 ай бұрын

Any socket sets out there using 12mm drive? 🤔 1/8" 1/4" 3/8" 1/2" 3/4" 1" Drives! 😂

@zajtoja 2 ай бұрын

The answer to the neverending discussion is easy. You prefer what you grow up using. The funny thing is that in europe we use inches for seemingly random stuff like wheels or steel pipes (in both cases its the diameter of a round object 🤔).

@court2379 2 ай бұрын

It wasn't worth inventing new standards for those things when the whole world was already using one. Creating a second would just create chaos. Camera mounts are 1/4-20 and 3/8-16 worldwide to my knowledge. Just another thing not worth creating a new standard for, just to change to using a different measuring stick.

@zajtoja 2 ай бұрын

@@court2379 There are norms for pipes in metric, I know of at least two, both used in metalwork and I'm pretty sure the local ones were here first, before inches ;) The cause for common use of inches in this case is smaller numbers (especially for wheels/tires) and interchangeability with imported items (for the pipes).

@court2379 2 ай бұрын

@@zajtoja They are often labeled 25mm or 50mm etc, but when you look at the nominal diameters they match to inches. Keep in mind though, pipe and tube are totally different. Tube has lots of different sizes and probably is fully metric in most of the world. Pipe has to use all the fittings so has very specific sizes.

@zajtoja 2 ай бұрын

@@court2379 Smh... Reading is hard, isn't it?

@007oskari Ай бұрын

@toddhazell925 2 ай бұрын

It is all about what you are comfortable with using.

@benreid7567 2 ай бұрын

I prefer scones with strawberry jam and thickened cream at teabreak or smoko as we of the antipodes prefer to call it.

@willridgway2513 2 ай бұрын

Any terminating digit representation of a number is indeed rational, but imperial units have odd choices of denominator. A thou can be converted to feet with a ratio, but a millimeter can be converted to a meter with a much more intuitive ratio... Imagine seeing a complex number on a parts tolerance 😅. That's why Descartes called these numbers 'imaginary'

@justinsturgeon1 2 ай бұрын

Did you know the inch is 100 percent derived from the meter. Us Americans couldn't figure out how how long an inch was so we based it off the meter. That's why the ratio is exactly 1/2.54

@1985230ce 2 ай бұрын

No I didn’t know that. I always thought that it was a coincidence that it was just two decimal places. However, knowing the origin of the two measuring systems, I question the validity of your statement.

@justinsturgeon1 2 ай бұрын

@1985230ce I was also unaware of that not too long ago and got educated on the topic. Interesting history. Has been since 1959. Biggest reason is that imperial is based of a "standard" and if you dont have acces to a standard or loose it cant be recreated. Metric system standard can be recreated if needed.

@chrisstephens6673 2 ай бұрын

You prefer what you know, that is natural. Rational imp system? A twelfth or a third of units is not rational neither are all the other fractions usedl. Metric everything is a tenth or multiple thereof or a times 10 or multiple thereof, that is rational! As for number and leter drills and the randon increase in size. Having said that being old and british i still think in feet and inches but work in metric, call me a confused hypocrite if you like but i know the measurements are rational. 😂😂😂😂

@creepyloner1979 2 ай бұрын

i don't get how americans do base ten math with measurements that are a mix of base ten and logarithmic fractions and random bs.

@charliechristian1097 2 ай бұрын

Howee is talking about how a fraction is a ratio…

@chrisstephens6673 2 ай бұрын

@@charliechristian1097 there would be nothing wrong with imperial if micrometers read in fractions.😉

@court2379 2 ай бұрын

@@creepyloner197912 and 16 have several integer divisors. 10 has 2 and 5. When you are doing things that require dividing things in thirds, half, quarters, etc, inches and feet make for nicer numbers. But it really depends on the industry. In the machine shop most everything is measured base 10. In tenths, hundredths and thousands of an inch. In finish carpentry, 1/16, 1/32. In house framing 1/8&1/16. The fractions can be easier to split on the jobsite. In the end it makes little difference either way. It's just a different measuring stick.

@Myrulv 2 ай бұрын

There is 63360 inches in a mile. There is 1760 yard in a mile. Using metric I can express any distance in mm, cm, dm, km or what not by just moving the decimal point. But the main thing here is standardization, not what you or me prefer. And the whole world is metric, except USA, Liberia and Myanmar. So clinging to imperial is kind of irrational. 🤗

@erniea4424 2 ай бұрын

The absolute WORST thing is the blasted steel rules that have inches along one edge, and metric shyte on the other edge. I actually bought 2 of them without noticing - maybe I should convert them to pry bars.. .

@frankmayer559 2 ай бұрын

I don’t get it… I learned to use metric systems and I never learned about how inches work, so to me it’s obvious, why I use the metric system. I didn’t learn to use inches and I‘m not interested enough to learn it now…

@frederickjeremy 2 ай бұрын

There are two kinds of countries in this world, those that put a man on the moon using an “inferior” unit of measurement, and those that are still trying to get there half a century later with their far superior system. Just because mcdonnalds makes a more convenient hamburger than the one i make on the grill at home doesn’t make it a better burger in any way shape form or fashon. Just my .02

@justinsturgeon1 2 ай бұрын

NASA uses metric from one American to another.

@nateritter4921 2 ай бұрын

Machinist hear. I absolutely prefer inches. And 30 shop I would at does to but most print come in as mm

@peteroleary9447 2 ай бұрын

In the American machinist's world, most of us use both, but prefer the inch system. We can take an inch, divide it in half, then divide that in half, half again, and so on. All along, we know the decimal equivalents of these fractional numbers, if it's appropriate to use that. The best of both worlds You don't often hear someone say "a quarter of a millimeter".

@Metric_Metalworks 2 ай бұрын

Actually it is common to say Something like half a Millimeter or a tenth of a Millimeter in countrys Like Germany

@Phantom-mk4kp 2 ай бұрын

@@peteroleary9447 no but you'll hear 0.25 of a millimeter, trig and math is a lot easier using metric and integrates with mass and volume easier too

@peteroleary9447 2 ай бұрын

@@Phantom-mk4kp Poppycock! Everything went to hell in a handbasket when they stopped using the pennyweight and hogshead for such things!

@Phantom-mk4kp 2 ай бұрын

@@peteroleary9447 On that note. Hey you know we've got this £ thing, and we've divided it up into 20 shillings, yes. Why don't don't we add another shilling to make it 21, and call it a guinea, great for face to face haggling and one offers 10℅ discount

@007oskari Ай бұрын

@charliechristian1097 2 ай бұрын

The craziest thing is that for lumber and other construction materials the world over, all of lumber is milled in imperial denominations and the metric folks make up some made up metric number to describe the material which is used… every whole number in feet is evenly divisible by 2, 3, and 4 inches, and the metric units are either too small or too large to be useful or relevant… cm and mm are too small to be relevant… meters are too large… imperial system comes from the Hebrew cubit which was given to human beings by the God of Abraham.

@jamescody9982 2 ай бұрын

Your method is fundamentally flawed. It's not "1/2 a mm"... it's "0.5 mm" metric adds directly this way without needing any LCD or ratios.

@tujuprojects 2 ай бұрын

He doesn’t get that metric system uses 10 as base like our numbering system does. Imperial doesn’t, you cannot change units by moving your decimal. Imperial has 12 and 3 base which screws everything.

@jamescody9982 2 ай бұрын

@tujuprojects People don't understand that if you can add money... pennies, dimes, 1s, 10s 100s... You're using metric. It's universally easier

@dmur612 2 ай бұрын

Are you saying .5mm *isn’t* equal to 1/2 a mm?

@jamescody9982 2 ай бұрын

@dmur612 it is, but when you're adding measurements together if you stick to one format it adds directly. Example: 100.25mm+10.50mm=110.75mm. But if you added it instead like 100&1\4 +10&1\2 you'd still need to mentally convert 10&1\2 to 10&2\4 before adding... it's just easier to add directly with decimals... millimeters.

@Sam-mv6rp 2 ай бұрын

Hear in the uk most everything is now metric but anything from the 70s or earlier is whitworth and imperial if I think correctly

@thomasd1513 2 ай бұрын

Americans do it OUR way. It’s the American way.🇺🇸

@MrHoundDoug 2 ай бұрын

*cough* English way... ;-)

@miles11we 2 ай бұрын

It ain't the American way tho lol we didn't invent imperial, we just kept it.

@theBrosDurham 2 ай бұрын

I use both

@waldemarii 2 ай бұрын

Metric only. When ever I hear you talking in inches it is really confusing and I have no idea what is the actual distance you are talking about. Even I know how much one inch is in metric. The problem is that half inch is not really unit of measurment. If someone says to me "half millimeter" I know what it is as in numerical value. We do have unofficial units of measurment in use in machine shops like "thent" (means 0,1mm) and "one hundred" (means 0,01mm) because they are convenient to use in spoken language (Finland). But having fractional and decimal systems like used with inches seems really impractical. When using decimal inches, it is like metric system but numbers are in impractical incraments and form. What I am trying to say that decimal inches are confusing because it is 10 based system but with fractional increments. In metric system we do not care what is fractional value of given measurement, 12mm rod is not 1-2/10 in our heads. Or is 1-10/5 the right way? Tell me, I really don't know.

@HOWEES 2 ай бұрын

I didn't realize fractions were the big hold-up. Surely a 1/2 inch can easily be understood as 0.500", and 1/8 as 0.125"? Etc etc. From my perspective it doesn't seem to be any trouble as the dimensions on the work I've been given have all been in decimal inches - even if the diameter was a nominal fraction. I think that as far as fractions go, they are more often used at the non-machinist level and persist as an automotive tool (socket) standard. -Cameraman

@waldemarii 2 ай бұрын

@@HOWEES When one is used to think in that way they are completely logical. In machining using metric system the standard unit is millimeter. Usually dimensions are nominal and if there is a tolerance it is stated after the nominal size. Lets say that I need to make 12,7mm +/- 0,05mm diameter bar, it can be 12.65 or 12.75. In decimal inches it would be 0,500 +/- 0,002, 0,4980 or 0,5020. This is simple and straight forward kinda, now as I think about it.. Yeah, it is this fraction based increments that make it so funny and for first hard to understand. Because we do not think in fractions at all. There is this really weird gap in metric system between millimeter and micrometer, there is missing two unit from between. Meter (m) is the base unit, then there is decimeter (0,1m), centimeter (0,01m), millimeter (0,001m), but then it jumps from 0,001m to 0,000001m (micrometer). So 0,0001m (0,1 millimeter) does not have any name in the system, but is really useful in machining. Also 0,00001 (0,01mm) does not have name in system, and it is highly useful. Many small bearing fittings are in +/- 0,01mm margin. We call these tenth and hundred. One german machinist here in youtube always talks in millimeters or micrometers. I dont know, maybe it is their way to use these units. We kinda made up those missing two. 😅

@joeyvanleeuwen5229 2 ай бұрын

Metric is hands down the easiest. Period. Square root whut?

@erniea4424 2 ай бұрын

.... but it isn't based in anything an average human can relate to...

@joeyvanleeuwen5229 2 ай бұрын

@erniea4424 why not? Everything is in ten's. Any average person has 10 fingers. I can teach anyone how to measure metric in less than 30 seconds.

@erniea4424 2 ай бұрын

@@joeyvanleeuwen5229 - oh, can you? 1 inch approximates the width of an average man's thumb. 12 inches approximates an average man's foot. I yard approximates the distance from an average man's nose to his outstretched fingertip. What body parts do you use to teach metric? It is based on the distance from the equator to the poles. WTF is logical about that? In order to measure anything using the metric system, you need some device. I can measure with astonishing accuracy using only my body.

@joeyvanleeuwen5229 2 ай бұрын

@erniea4424 lol you're definitely not hired. Measuring with body parts omfg. Also love how you use the word approximate when talking about measuring. Tell you what, you measure with your forearm or whatever and I'll use my metric tape measure. Peace

@erniea4424 2 ай бұрын

@@joeyvanleeuwen5229 - ok, here is a challenge for you: tell me how you would measure a linear distance (any distance - 100 meters, 2 kilometers, whatever) on land using the metric system, and NO tools; only your body. I'll wager I can do exactly that with accuracy of 2% or better, using nothing but my body. Tell me - I'm waiting...

@Phantom-mk4kp 2 ай бұрын

Metric makes more sense, just takes time to get used to imagining the measurements appearance in your mind if you've been brought up on imperial system

@duckaroobonzai2648 2 ай бұрын

People who don't know math like metric people who can actually do math see them exactly the same.

@zajtoja 2 ай бұрын

@@duckaroobonzai2648 That's your weird opinion, buddy. I grew up in Europe, used metric my whole life and only got a grasp on imperial because I watched NBA. I'm pretty decent at math, I teach a lot of neurodivergent kids and they do fine with my help. Imperial still doesn't make much sense to me, even though I'm able to use it without problems. The only thing that matters is which system you used growing up, that's the one you prefer.

@duckaroobonzai2648 2 ай бұрын

@@zajtoja then you're not good at math. I'm a Machinist I literally use this everyday. You do realize you use the same ratios in metric then you do in imperial. You still break down millimeters into halves eighths and sixteenths. You're never going to get any measurements to be perfectly 1/10 of something lmfao. Thinking it's better because you don't know how numbers work doesn't help your case.

@duckaroobonzai2648 2 ай бұрын

@@zajtoja I grew up on imperial I have to switch between both of need be. I deal with measurements of .001 inches. Now that kinda looks metric 😲

@Phantom-mk4kp Ай бұрын

@@duckaroobonzai2648 don't think I've ever heard anyone quote 1/16 of a millimeter

@DamBlairFam 2 ай бұрын

12-base is better for fractions

@flatmoon6359 2 ай бұрын

I still think in thou's,trained in imperial, but use metric every day.

@faafo2 2 ай бұрын

I could see this coming from a kilometer away ...

@joeyvanleeuwen5229 2 ай бұрын

@@faafo2 A kilometer and 11/64!

@frederickwilt5541 2 ай бұрын

Preferring imperial is simply insane.

@jakhamar55 2 ай бұрын

Depends on where you work. Oil patch is API and its all inches. Having large measurements in mm is just bizarre.

@frederickwilt5541 2 ай бұрын

@@jakhamar55 That's why you have centimeters, decimeters, meters, dekameters, hectometers, kilometers and the rest.

@jakhamar55 2 ай бұрын

@@frederickwilt5541 yes of course but when you are talking drawings in a machine shop it is in mm.

@frederickwilt5541 2 ай бұрын

@@jakhamar55 If using metric means only using mm then using imperial should mean only using 1/32" if you want to be consistent. I would have no problem working off a drawing with different metric units, would you?

@jakhamar55 2 ай бұрын

@@frederickwilt5541 Nonsense you are not understanding what i am saying. You go do your metric stuff and i will do my inch stuff and we will be happy.

@c3sPAze 2 ай бұрын

I pefer toe nail clippings

@dancearoundtheworld5360 2 ай бұрын

hard to roll up 25 feet of that

@Dieselpwr 2 ай бұрын

Inches is way better for the skilled modern American

@michaelidarecis 2 ай бұрын

Metric is Me-Trick

@leeroyholloway4277 2 ай бұрын

12 is a more malleable number than 10, IMO.

@shane5968 2 ай бұрын

Metric systems

@JudahEyes 2 ай бұрын

Yeah, definitely don’t use square root for a measurement!

@GimpGladly 2 ай бұрын

Good point, never use triangles.

@jakeclauson9863 2 ай бұрын

😅 don't think that's what they ment by irrational 😆😆

@thigtsquare950 2 ай бұрын

Metric system was order under one of the Governments of the French Revolution. For people it’s simpler to count with the numeric base 10 because we usually have 10 digits in our hands. However, base 12 numeric systems is “better” because it has more factors (making fractions easier because it yields whole numbers e.i. 1/3 = 4, 1/4 = 3 instead of 1/3 = .33333 or 1/4 = 2.5). There are proponents of the base 12 numeric system and you can use the 12 falanges in your hand to count to 12 (not counting the ones in your thumb).

@arnearne12345 2 ай бұрын

buddy you can subdivide by any number forever and to do what you suggest you just multiply by fractions

@ollierobin 2 ай бұрын

3937

@paisaconstructiondavid1964 2 ай бұрын

The important point is to learn both and let go of pride. The less common topic is that some countries use a coma instead of a period to separate the whole number from the decimal. 😂 just in case you were interested in trowing more gasolina into the fire 😂 I have discovered that working with wood is very convenient to use a tape measure with both and using the inches for rough measurements and millimeters for the accuracy. It's simpler math to add one mm. It's a little more challenging when it's 3/64 +

@northmanlogging2769 2 ай бұрын

where metric falls apart is the smaller tolerances, say sub .0005" Micrometers are only so accurate, can they read .0001" sure, but... they are only accurate to .0002 or so, which is .007mm and metric mics only read to .005, so in turn are only accurate to .01 (.0004")even worse with calipers. Essentially if you have 3 hands on a clock, Inch uses all three, where metric is only using the hour hand, and calling it good enough. One of the myriad of reasons metric threads have looser tolerances, and tend to strip out faster, they simply can't hold tight enough tolerances with tooling commonly available.

@northmanlogging2769 2 ай бұрын

yeah yeah yeah, digital stuff reads to .xxxmm... still only accurate to .005mm.. and most will end with a 0 or 5 so?

@Years-qy7me 2 ай бұрын

Rubbish you can get 10ths micrometers. Also about the threads, you're incorrect, a metric fine thread is far stronger than Whitworth which is so course for its diameter that the core of the bolt is much smaller. UNF is a nice thread to use, UNC just the same as standard Metric.

@northmanlogging2769 2 ай бұрын

@@Years-qy7me well... no one uses whitworth anymore for a reason for starters (because its a deeply flawed system) continental folks just go ahead and ass-u-me that us americans are still using some outdated British system... its annoying and hilarious But while yer at it, just look at the accuracy documentation on literally any reputable measuring device, compare it to what it actually reads, and get back to me. Then spend the better part of 3 decades making both metric, and SAE threaded parts and noting that metric is ALWAYS a sloppier fit, so much so that many would be out of tolerance in SAE. And yes, there are different classes of thread fit in both metric and SAE, however, the scrap rate goes through the roof on the tightest metric threads, because its asinine to hold them that tight. So generally they specify a less tight fit, just to keep scrap rates down. Seriously though, do the math, max PD of a external thread, and min PD of an internal thread, pick any metric thread, and compare it to any similar sized SAE thread 1/4-20 vs M6x1 is a great place to start, remember to calculate using 25.4, cause the idiot standard of using .3934, is a rounded number...

@edwardhuff4727 2 ай бұрын

@@northmanlogging2769 0.0002 × 25.4 = 0.00508, not 0.007. Just saying.

@northmanlogging2769 2 ай бұрын

@@edwardhuff4727 oop.. missed that in proof read, point is still made though, metric simply doesn't read small enough to be that accurate

@blindvegan 2 ай бұрын

I worked in industrial engineering for years we always used metric

@DaveElectric 2 ай бұрын

But machinist use thou ...not inches

@beefchicken 2 ай бұрын

Metric is fundamentally irrational. The original 1781 definition of the meter was based on the circumference of the earth: 1 meter = (diameter of earth in meters) × π ÷ 40,000,000 π is fundamentally irrational, therefore metric is irrational. (metric aficionados: before you comment, keep in mind that this might be a joke)

@HOWEES 2 ай бұрын

I see you got it, A+