What is your preferred measurement scale?

[Matt Mattingley]

I’m somewhat of an old gear head Imperial system . I’ve come to the point that I don’t even like writing down fractions anymore. I’d rather write down decimals of an inch (ie.12.656 than 12 21/32)

If I’m calling it out, to be cut by a partner, I work to 1/16” Light, half, or heavy. This gets me close to 1/64”

One of my newer machines is metric(planer). Some of my more recent drawings are now metric. But I still preferre to use Imperial. 95% of my machines are imperial and all my measuring instruments are Imperial.

How goes your struggle?

How many guys are still using the vernier scale for 1/128 or 1/256???

Thank you 25.4!

[Jim Becker]

Honestly, except for on the CNC where it’s easiest to use decimal inches, I’ve moved to metric for all my projects.

[Leo Graywacz]

Swap between digital inches and fractional inches.

[Mike Henderson]

Metric is a lot simpler but I still use Imperial fractions for most of my work.

Mike

[Matt Mattingley]

Don’t get me wrong. I love millimetres too. If I get a drawing that says to make something 171.45mm, I know what they’re talking about.... it is 6 3/4 of an inch. 1000 mm equals 39.37”.... but I usually have to convert everything to a decimal of an inch.

[Andrew Hughes]

I have no problem using the Imperial system.
Most of the time I'm reference building so exact numbers mean nothing.
If I'm making a table I do check to see if it's 30 inches tall and the right length

[Wayne Lomman]

As I am a bit prone to point out, my struggle with metric was brief and about 40 years ago when we changed from imperial by federal legislation. Metric or imperial is not ideology or anything, its just a number put to a size. Use what you like and to hell with everyone else. Will one or the other improve your standard of workmanship? I think your skills might be a bit more impressive than the measuring system. Cheers

[Rich Engelhardt]

Depends..
Over 6" and I use Imperial & fractions.
6" and under, I use the digital caliper I got from HF for about $20 and I toggle between everything. Metric is the easiest, but, a push of the button converts to fractions.

[Martin Wasner]

Holy crap, what are you building that requires precision down to 1/256"? And how in the world did you maintain those tolerances?


I use decimal imperial
I use fractional imperial
I use decimal SI
I use Factional SI

[Pete Staehling]

I too most often use metric inches for smaller measurements, like under 6", and inches and fractions over that.

[jack forsberg]

i use Digital calipers quite often in woodwork and generally work in Imperial but with the push of a button it’s converted to metric. Anything longer than my caliper is Imperial. Although I have a 40 inch Digital read out . I think with the advent of the digital readouts for the machine now days it’s pretty easy for anybody to work with any tolerance now. It’s most greatest asset is to Repeatable set up’s . Still set all my knives To decimal inches

[John Kee]

Lets be honest almost every measurement done in North America that is metric is just a conversion from Imperial measurement, that's why we get some of the wacky numbers seen on drawings. Use what your brain was originally trained to use and convert when/if needed. Like Jack said it's typically with a press of a button. Like Wayne said its been about 40 years since the conversion in both of our countries, I don't know about his but Canada is a still a mish mash of Imperial with adapted metric measurement.

[Rod Sheridan]

If I'm the furniture designer, it's metric.

If I have a plan in Imperial units, then I use that.

I find metric a lot easier to use and design with, for example I'll make stock 20mm thick, makes for easy arithmetic. It helps that my planer is metric as well..........Rod.

[glenn bradley]

At my age I've lived through the attempts at conversion from imperial to metric in the U.S.. The result is I am pretty comfortable with both for lengths and volumes. Still not good at guesstimating KPH but, I was never really good at MPH either ;-)

[Derek Cohen]

I’m somewhat of an old gear head Imperial system . I’ve come to the point that I don’t even like writing down fractions anymore. I’d rather write down decimals of an inch (ie.12.656 than 12 21/32)

If I’m calling it out, to be cut by a partner, I work to 1/16” Light, half, or heavy. This gets me close to 1/64”

One of my newer machines is metric(planer). Some of my more recent drawings are now metric. But I still preferre to use Imperial. 95% of my machines are imperial and all my measuring instruments are Imperial.

How goes your struggle?

How many guys are still using the vernier scale for 1/128 or 1/256???

Thank you 25.4!

I think better in imperial, that is, I can envisage 12" more easily than 300mm. 48" or 4' is easier than 1200mm (actually 1219mm roughly). So when I measure up, to gauge the size of something, I prefer imperial.

However, when I draw up a plan, computing fractions is a pain. For example, 4 3/4" + 3 1/16" = aaaaahhhh!! :eek: I much rather go 120mm (because you would use round numbers) + 75mm = 195mm. So much easier! :) So, metric for drawing up.

Now tape measures and scales are very imprecise for multiples, such with the many drawer blades I need to mark in the apothecary chest I am building. Far better to use dividers ...

https://s19.postimg.cc/o2p1tdhtf/Template2.jpg

The other tool to use when transferring measurements is a cutting gauge.

http://www.inthewoodshop.com/Furniture/BuildingTheDrawers_html_m5b245677.jpg

Regards from Perth

Derek

[Tony Pisano]

Give me good old imperial. I can't think or visualize in metric. I know in my head that 7/16 is .437 and I looked it up in metric and its 11.1125. How is that any easier? If you tell me to take 5 or 10 thousanths off of something, I understand how much that is and can do it. Tell me to make it 3 millimeters, or go about half a kilometer and take a left, or the temperature is 40 degrees centigrade, or something weighs 5 kilograms, and I just stand there and scratch my head!

[Tim Bueler]

I spent my life in the construction industry so I think in fractions though I have no problem toggling between fractions, decimals and metric. I have a couple conversion charts tacked on the wall and my Construction Master calculator for larger conversions if needs be. In the shop it's just me. I jot down numbers in 16ths w/o the denominator, i.e., 7 = 7/16", 8 = 1/2", etc. I also use + and - signs to get me to the 64th w/o having to do the math though if things get this critical I usually use a story stick or some other direct reference.

[Jamie Buxton]

Decimal inches, for everything. Decimal is much easier to do math on than fractions. Inches makes for easy conversation with customers.

[William Adams]

Mostly I use Imperial inches and traditional fractions --- sometimes I'll grab a DTP Pica/PostScript points ruler from my desk if I need it for a measurement to come out even. Using metric for handwork annoys me with all the odd numbers and the frequency of dividing stuff by thirds and it not coming out to a nice even dimension (72 points per inch ensures that such a division will come out to some even number, or at worst, a half-way mark --- I never feel confident of marking off a third or two-thirds of a millimeter).

Using metric for CNC, except that I can't find all the information there as metric --- if someone has a source for:

- chiploads
- metric formulas
- typical metric units used

I'd be grateful.

[Rod Sheridan]

At my age I've lived through the attempts at conversion from imperial to metric in the U.S.. The result is I am pretty comfortable with both for lengths and volumes. Still not good at guesstimating KPH but, I was never really good at MPH either ;-)

I agree Glenn, we went metric in the seventies when I was in high school. Science was taught in the SI system, and I was too young to really have developed a fondness for the Imperial system.

I've never had a drivers license when we weren't metric for road signs, when I drive in the US I simply keep the GPS in metric units so I have a feel for the road speed.

That said 3 of my motorcycles are in Imperial units. My oldest daughter was loathe to ride her Honda CB350, she always wanted to borrow "our" R90/6 BMW. One day she remarked how everyone drove so slow through the school areas. I said that it was odd, her response was that the speed signs were 40 and everyone was doing just over 20.

I remarked that the BMW was in miles per hour and she said "it's in what"?.................Too funny...............

As for other measurements, if you gave me one pound of meat and asked me how heavy it was, I wouldn't know. I also wouldn't know what it was in the metric system. I just know that at the deli, I ask for 300 or 400 grams of meat. Now, if you really want some fun, ask someone how much they weight in metric units, guaranteed they come up with a number of kilograms...............Rod.

[Rod Sheridan]

Give me good old imperial. I can't think or visualize in metric. I know in my head that 7/16 is .437 and I looked it up in metric and its 11.1125. How is that any easier? If you tell me to take 5 or 10 thousanths off of something, I understand how much that is and can do it. Tell me to make it 3 millimeters, or go about half a kilometer and take a left, or the temperature is 40 degrees centigrade, or something weighs 5 kilograms, and I just stand there and scratch my head!

Tony, it's the Imperial system that's difficult.

I take a nice piece of wood, planed to 20mm thickness and it turns out to be 0.787". How am I going to measure or add that?

As you've just seen, the issue is that you shouldn't be converting, you should either make your piece of wood 3/4" thick or 20mm thick.

The problem is that you have no familiarity with the metric system, you didn't have any familiarity with the Imperial system until you learned it.

To this day I have no idea what the unit for mass is in the imperial system, and I have to use a conversion factor from power to obtain horse power for a motor.

It's all what you're familiar with, however working in the metric system can be easier than the Imperial system, however it's application dependent.......regards, Rod.

[Tim M Tuttle]

Base 12 FTW

[Peter Christensen]

Usually 'round dis long, so high and yay thick gets me there. ;)

[Rod Sheridan]

Usually 'round dis long, so high and yay thick gets me there. ;)

That's so true about a lot of the things we make isn't it?

[Carlos Alvarez]

I have trouble visualizing medium-sized metric measurements. I have zero issue visualizing 15mm, or a kilometer. But when I hear 783mm, I have to really think, while 30" would be an instant visual. I don't know why that is.

All of my tools have fractional SAE markings, and some but not all have metric markings. I have SAE drill bits mostly, very few metric. When measuring differences, it is obviously so much easer to say "cut this 1mm shorter" or "make it 29mm instead of 30mm." Overall I'm OK with either but since everything has inch fraction markings, that's my predominant working measurement. Oh, and I often have various helpers who are firmly stuck in inch fractions, so telling them anything else would just create confusion.

[Glen Gunderson]

I have trouble visualizing medium-sized metric measurements. I have zero issue visualizing 15mm, or a kilometer. But when I hear 783mm, I have to really think, while 30" would be an instant visual. I don't know why that is.


Same here, weird how that works.


For projects, I usually do the conceptual stages in imperial just because I can visualize the normal sizes of things I build better in inches and feet. I can get by in metric at this point, but it requires more conscious thought to visualize the sizes. But when it comes to time to take precise measurements and start building I usually switch to metric. I just find it so much easier for dealing with offsets and overlays with cabinetry, or really anything where you're adding or subtracting a bunch of numbers. And even with my relative inability to quickly visualize some metric sizes, I find using it has reduced errors and sped up my work.

And like Rod mentions, I size the stock to suit metric. So what might be 3/4" or 13/16" thick and 3.25" wide rails and stiles in imperial would be 20mm thick and 80mm or 85mm instead (unless I'm matching something existing of course).

[Carlos Alvarez]

One thing people get hung up on is the idea that stock needs to be 3/4" or whatever. No, it just needs to be consistent. While working in metric once someone asked me how I was going to get my 20mm boards to be 3/4" to "finish" the project. Er, what? Come to think of it, the digital readout on my drum sander is currently set to metric.

[Lisa Starr]

I work in imperial decimal most of the time, though I will use metric when necessary (Cup Hinge Locations). Of course, I work in a machine shop, so decimals come easily to me and I know most fractional/decimal equivalents.

[johnny means]

I have to be comfortable switching between them all. But at the end of the day I still visualize in fractional inches. I can strike a mark within an inch of 48 inches without measuring but I wouldn't recognize 400 mm if it slapped me in the face.

[Carlos Alvarez]

My eyecrometer is calibrated in SAE fractions also. I can usually hit closer than 1/8 by eyeball only.

[Bruce Page]

One time machinist so my preferred system is decimal. I can and do use metric when needed but it's not my go to.
I worked as a machinist at a government R&D lab (Los Alamos) when Jimmy Carter tried to move the country SI Metric. All our part drawings were then drawn in metric. We would sit down and convert all the dimensions to decimal..:rolleyes:

[Tom Bender]

Since most wood is available in feet and inches and quarters (4/4, 6/4 etc), it's easier to stay with that. I work to thirty-seconds.

[Phillip Gregory]

I’m somewhat of an old gear head Imperial system . I’ve come to the point that I don’t even like writing down fractions anymore. I’d rather write down decimals of an inch (ie.12.656 than 12 21/32)

If I’m calling it out, to be cut by a partner, I work to 1/16” Light, half, or heavy. This gets me close to 1/64”

One of my newer machines is metric(planer). Some of my more recent drawings are now metric. But I still preferre to use Imperial. 95% of my machines are imperial and all my measuring instruments are Imperial.

How goes your struggle?

How many guys are still using the vernier scale for 1/128 or 1/256???

Thank you 25.4!

I personally use fractional inches as being in the US, the majority of the stock, fasteners, and tooling are available in imperial measurements. Fractions are easier to work with for the relatively imprecise measurements used in woodworking. It's easier to do arithmetic on fractions in your head compared to decimals. Wood changes its own dimensions on you with humidity changes, so it cannot be a high precision medium like metal, so you don't need to get down to the thousandths of an inch precision that make fractions difficult to use. Being able to come up with 3/16" is half of 3/8" in your head is far easier than coming up with 0.1875" is half of 0.375".

I do have a cheap rule type vernier measured in fractional inches (down to 64ths) for measuring stock thickness. I have a digital vernier calipers I use for metalworking tasks that is accurate to 0.0005" but I don't use it for woodworking as that level of accuracy is unnecessary. If you're a fuzz thick, a few strokes with a sanding block will get the dimensions correct, and if you're a fuzz long, touch the end against a disc sander and now it's good.

I do not do much work in metric as nearly all of my tooling, all of my stock, and all of my equipment is in imperial units. The one piece of tooling that's metric is my shaper's Euroblock 40 mm insert head (which has an Imperial 1 1/4" bore), which I grossly convert to "good enough" fractional inches and use accordingly. Nobody's going to be able to tell the difference between a 3 mm (0.118") roundover and a 1/8" (0.125") roundover.

[Josh Kocher]

Metric all the way...

[John Gulick]

I can recall in the '60s a teacher telling us the metric system would take over in 5 or so years. It seems as though we never made it. I am old and prefer inches/feet/yards, etc. In the '70s I worked in the machine trade and learned how much a .001 is. Generally I use a Starrett 6" dial caliper, but also have a good size assortment of micrometers. Inch measure. I also set our machines up and keep them in tune.

[Randall J Cox]

I'm old too (70+). However, I lived in europe for many years in the USAF and the metric system is so much easier to deal with than the imperial system. The US might even be the last holdout in the whole wide world that hasn't fully gone metric. I hate using fractions but finally found a fraction calc for my phone that I use that takes the bad out of it, mostly. We need to get on with finally converting and ignore all those who want to stay with the imperial system, they have no idea... Randy PS this ought to rile up some.

[Bill Jobe]

I think it must be something that a person developes at an early age. The push to convert to metric in the US has failed miserably. As a result most products leave the factory with a bizarre combination of metric and SAE.
I grew up in the 50s and by the time metric was being pushed it was too late for me. My mind thinks in inches, decimals, miles, mph and so forth. In the shop I used metric dial calipers given to me by a forman who had been a machine operater, his personal piece along with a nice leather holster, and used a calculator to convert it. In my mind I supposed that would familiarize me with metric. Didn't work.

[Osvaldo Cristo]

I’m somewhat of an old gear head Imperial system . I’ve come to the point that I don’t even like writing down fractions anymore. I’d rather write down decimals of an inch (ie.12.656 than 12 21/32)

If I’m calling it out, to be cut by a partner, I work to 1/16” Light, half, or heavy. This gets me close to 1/64”

One of my newer machines is metric(planer). Some of my more recent drawings are now metric. But I still preferre to use Imperial. 95% of my machines are imperial and all my measuring instruments are Imperial.

How goes your struggle?

How many guys are still using the vernier scale for 1/128 or 1/256???

Thank you 25.4!

Although I can work in imperial fractional, by far it is much more convenient to me to work with (decimal) metric.

Additionally I work with only three significant places for all measures, except in a very few cases where we can have an accumulated unacceptable error. From my experience, three places are good enough for virtually all woodworking needs, so there is no sense to work with 12.656 cm... go to 12.7 cm as it will be good enough for (most) woodworking... as you can see, my training to use slide rules in my early life still brings consequences... :D

All the best.

[Chris Parks]

I think it must be something that a person developes at an early age. The push to convert to metric in the US has failed miserably. As a result most products leave the factory with a bizarre combination of metric and SAE.
I grew up in the 50s and by the time metric was being pushed it was too late for me. My mind thinks in inches, decimals, miles, mph and so forth. In the shop I used metric dial calipers given to me by a forman who had been a machine operater, his personal piece along with a nice leather holster, and used a calculator to convert it. In my mind I supposed that would familiarize me with metric. Didn't work.

Whole countries have converted with people who grew up in the 50's, me included. Looking from the outside in it is inevitable that the US will go metric, if not as a hard political decision then an erosion of imperial brought on by trading with the rest of the world. Automotive products are an example of one industry that has already changed or is in the process of it.

[Peter Christensen]

Since the bulk of manufacturing is using CNC machines of one kind or another it would only be a matter of selecting metric on the display and that side of change is done in an instant. The old argument that the cost of changing the machines would be too high is pretty much done unlike before when the work was done with manual machines. All the other arguments will fade as companies realize they can't sell goods abroad unless they are metric.

[Andrew Seemann]

I do US imperial with fractions; its what I have used for woodworking for the last 40 years and what almost all of my tooling is. I can "see" inches and halfs and quarters and eighths and sixteenths and thirty seconds; I can't do that in metric. Metric units always seemed clumsy, millimeters and centimeters seem too small for furniture sized projects and meters too big. Base 12 is much easier to halve, third, and quarter. Base 10 not so much.

Back in my machinist days, I did both decimal inches and metric. I preferred inches because thousands were easy to work with, but I would do metric when somebody gave me a plan in metric. Back then I could convert back and forth in my mind, not anymore unfortunately.

[Charles Taylor]

Inches and fractions here. Nothing against SI; it's just mental inertia that keeps me using traditional measurements.

[Martin Wasner]

I love these threads. "My sitck is better than your stick." Even though there's no real difference.

[Chris Parks]

I do US imperial with fractions; its what I have used for woodworking for the last 40 years and what almost all of my tooling is. I can "see" inches and halfs and quarters and eighths and sixteenths and thirty seconds; I can't do that in metric. Metric units always seemed clumsy, millimeters and centimeters seem too small for furniture sized projects and meters too big. Base 12 is much easier to halve, third, and quarter. Base 10 not so much.

Back in my machinist days, I did both decimal inches and metric. I preferred inches because thousands were easy to work with, but I would do metric when somebody gave me a plan in metric. Back then I could convert back and forth in my mind, not anymore unfortunately.

That is curious because your currency is base 10 and I presume you do not have trouble with that.

[Matt Mattingley]

Although I can work in imperial fractional, by far it is much more convenient to me to work with (decimal) metric.

Additionally I work with only three significant places for all measures, except in a very few cases where we can have an accumulated unacceptable error. From my experience, three places are good enough for virtually all woodworking needs, so there is no sense to work with 12.656 cm... go to 12.7 cm as it will be good enough for (most) woodworking... as you can see, my training to use slide rules in my early life still brings consequences... :D

All the best. I am a woodworker and I am a metalworker. I do not work in centimetres (cm) I work in inches with 3 to 4 decimal points, I work in millimetres (mm) to two decimal points. I was a woodworker first, i became a metal worker and kept my passion as a woodworker. 12.656 cm is a mile away from 12.656” inches (or vice versa)

12.656 inches = 32.14624 cm
12.656 cm = 4.982677” (inches)
12.656 inches - (subtract) 12.656 cm => A difference of 7.6733” (inches) or 19.49 cm(, or 194.9mm)

If I am grinding a spindle to 30 mm or if I’m grinding the spindle 1 1/4 inches, no woodworker cares so long as it works and fits nice to their purchased head.

I get this question occasionally, what’s more precise a metric micron or in imperial Micron?????? Then there is...I don’t care, make my machine work...

[Andrew Seemann]

That is curious because your currency is base 10 and I presume you do not have trouble with that.

I'm not typically trying to convert currency by a third or the golden ratio :)

[Chris Parks]

I'm not typically trying to convert currency by a third or the golden ratio :)

Metric countries don't seem to have that problem and apart from the US that is basically the rest of the world.

[Matt Mattingley]

At no time I’ve ever considered that (one measurement scale is better than the other, or)one is more superior to another. Measurement is a source of reference. Any source of reference is determined by X.

This is a preferred measurement thread and machine readout thread and how you deal with the machines readout if it’s not in your preferred scale of measurement.

I don’t even care if this goes off topic. I just am wondering how others deal with metric machines when used to Imperial Machines in their shop?

My old thickness planer used to take 0.100 per hand wheel rotation. My new thickness planer takes 2 mm or 0.079”.

[Bill Jobe]

Just thought I'd throw in the rod, since no one else has mentioned it.

[John K Jordan]

How goes your struggle?...
Thank you 25.4!

Good grief, give the guy an inch and he takes a meter. :)

I guess I'm sort of bilingual but only after years of force-fed diet.

On the milling machine I think in thousandths since my dials are in thousandths. For constructing things like the shop and farm buildings, it's inches and feet for me. For weight I use grams for small things and ounces/lbs for heavier things. I have no idea how many kilograms one of my llamas weighs. When mixing chemicals I measure small amounts of liquids in milliliters and larger amounts in cups and gallons. I bottle honey by the lb or gallon because that's the way the containers come but the labels are required to have both metric and imperial. For me pressure is always in lb/sq in, vacuum in inches of mercury, and temperature is in F except in the darkroom (which I don't have anymore). I'm slowly getting better at guessing metric thread pitch. Hey, how come there is not both imperial and metric standards for time??! Ha.

Fortunately, digital calipers and other electronic measurement things are switchable as needed.

In the shop when measuring something small to fit or using a center-finding ruler I find metric a lot quicker and less prone to error. After some practice I can now visualize and judge sizes in CM and MM better than 32nds. Since many vehicles and mechanical things these days use metric fasteners I'm finally getting to where I can usually guess if I need a 10mm wrench. But although I can often estimate a 10th or half mile I don't thing I'll EVER get the hang of kilometers.

Fortunately, in woodturning only the relative size is important most of the time. I have plenty of dividers and calipers for this and verniers I use for the distance, not the numbers.

It's tough for some of our elderly brains. However, since it looks like metric is not going away for the good ol' US of A consider this: when kids and grandkids are in the shop teach them to work in both metric and inches when they are small. Life might be easier for them if they grow up bilingual!

JKJ

[Martin Wasner]

I don’t even care if this goes off topic. I just am wondering how others deal with metric machines when used to Imperial Machines in their shop?



You know both systems and how to convert between the two. I have two SAC shapers, one reads in imperial, the other in SI. Not an issue. Every other euro made tool I've got has a scale in both so no math required.

Almost all of the hardware we use is metric, no big deal.

It's just a stick. In a cabinet shop, there's no advantage to either other than base 16 fractions can be handled mentally easier by most than going four decimal places deep. But, you need to be able to do that as well because pounding numbers into a programmable stop as a fraction takes too long.

You really need to be able to flip around from both measurement systems and the decimal and fractional equivalents of both.

I will say feet have no place in a cabinet shop, we're simple folk and that's confusing when you've spent your entire career just reading inches on a print.

[jack forsberg]

I’m able to handle any measurement system. one thing I do find interesting is to see how woodworkers adapt to metalworking measurements. Generally woodworkers will tell you that thousands of an inch don’t matter in woodworking because the wood is expendable and contracts . I believe what they mean to say is that the tolerance in woodworking is not necessary down to a 1000th of an inch . What’s important to note is that 250 of them make a quarter of and inch to an Accuracy of 1000. Their usefulness is in position And accuracy.Now I can understand the argument that this is not a useful strategy in woodworking but it is certainly one when it comes to setting up machines for woodworking. It has in recent years become so affordable to own anything remotely accurate for woodworking so not to have such a measuring device is no longer an argument. We often by sand papers in metric in microns but very few people are aware of micro inches and in fact machinist gage blocks are set to an accuracy of one millionth of an inch. The accuracy of such numbers can only be attained in instrument rooms who’s climate is controlled at a constant temperature. Measurement is not as important as accuracy.

[Joe Calhoon]

I converted to metric in the shop when we started building Euro doors and windows. The hardware for those is like the 32mm cabinet system X 50. When we built cabinets decimal inches worked well. The Martins convert back and forth at the flip of a switch and most of the other digital machines pretty easily if needed and all my manual machines have dual scales. The digital stuff always stays on metric though. I still measure jobs in imperial, don’t know why...
Always do shop drawings in imperial for the customer but they easily convert to metric in the cutlist and cad programs.

Its a curse to have to work both systems but that’s where we are. Feet and inches from architects and contractors are a major pain but do not see that changing in the near future. Shops in Europe work in mm even at the long lengths.

[Chris Parks]

As has been said a few times before whenever this subject crops up, don't convert, design in the system you mean to build in. Neither system has any advantage in actually measuring the length of something, the advantage metric has is in calculation and by definition no fractions because everything is designed to one whole millimetre.

[Pat Barry]

Inches and fractions thereof. Hopefully no need for less than 1/64 as I can' t see anything less than that so clearly. All my measuring tools are inches. The only reason I use metric is because I have to. If I had CNC I would still use inches, just decimal instead of fractions. Thanks

[Curt Harms]

Inches and fractions here. Nothing against SI; it's just mental inertia that keeps me using traditional measurements.

I think that's the case for most of us, plus metric fasteners are not as readily available and therefore cheap as Imperial. I find it sorta funny that people talk about xx.xxxx millimeters. I wonder if those people know how small even .1 of a millimeter is. I'd be surprised if most woodworkers using metric measure to less than .5 mm, or about 1/50" or .02"

[Jim Becker]

For woodworking, I shoot for .5mm Curt and even that's tenuous given moving one's head while measuring can change the precision. :) 1/32" for inches is the general expectation when I work in inches for general woodworking. But I also work in a way that I establish overall dimension and then measure off the assembly to get a tight fit by sneaking up on it when that's a practical thing. With CNC, it's normal to talk about thousandths for some things because the tool can support that, unlike most human fingers and eyes.

[William Adams]

Metric countries don't seem to have that problem and apart from the US that is basically the rest of the world.

Yeah, except for those layouts I keep getting from metric countries where the width of a two column ad != col. width * 2 plus gutter width --- and casting off the manuscript doesn't work out correctly due to rounding errors as opposed to the actual typesetting page count.

And I still don't have an answer to a fully metric set of formulas for CNC chipload and feed/speed calculation:

https://sawmillcreek.org/showthread.php?264382-Metric-units-and-formulas-for-machining

[Bill Jobe]

"One thing people get hung up on is the idea that stock needs to be 3/4" or whatever. No, it just needs to be consistent."

There's a brilliant mind.

[Carlos Alvarez]

That is curious because your currency is base 10 and I presume you do not have trouble with that.

We do, have you tried to split $10 three ways?

[Pat Barry]

"One thing people get hung up on is the idea that stock needs to be 3/4" or whatever. No, it just needs to be consistent."

There's a brilliant mind.
if the piece is intended to fit, for example into a 3/4" dado then it will be much more important that the piece be 3/4" thickness where it fits the dado, and its lesser importance if it is consistent elsewhere. Answer is that the dimensions depend on their purpose.

[Bill Jobe]

if the piece is intended to fit, for example into a 3/4" dado then it will be much more important that the piece be 3/4" thickness where it fits the dado, and its lesser importance if it is consistent elsewhere. Answer is that the dimensions depend on their purpose.

One of us has clearly misunderstood Carlos.

[Carlos Alvarez]

One of us has clearly misunderstood Carlos.

My career in tech has always been about getting people to stop holding on to old "requirements." The way it goes is that you propose a new way to solve the problem, and the users give you a long list of reasons it won't work, mostly because they get hung up on doing all the old detailed steps as if THEY were the requirements. A guy working in metric would never build 3/4" dados; he'd make them 19mm. Sure, that's "the same" and they can often interchange also, but that's not the point. A lot of my builds have no specific number. I just finished a build where I absolutely cannot tell you a single dimension. I just ran down the cutting tools until I got a consistent set of pieces for the look I wanted. Is it metric or SAE?

[Bill Jobe]

My career in tech has always been about getting people to stop holding on to old "requirements." The way it goes is that you propose a new way to solve the problem, and the users give you a long list of reasons it won't work, mostly because they get hung up on doing all the old detailed steps as if THEY were the requirements. A guy working in metric would never build 3/4" dados; he'd make them 19mm. Sure, that's "the same" and they can often interchange also, but that's not the point. A lot of my builds have no specific number. I just finished a build where I absolutely cannot tell you a single dimension. I just ran down the cutting tools until I got a consistent set of pieces for the look I wanted. Is it metric or SAE?

Neither. I would refer to it as "custom".

[Steve Demuth]

We do, have you tried to split $10 three ways?

It's easier to split 10" three ways? The closest you'll get on most inch rules is 3 11/32" - but very few woodworkers could do that quickly and easily in their head.

So, quickly now, divide a foot five ways in fractional inches.

My point is that in any system of measurement lots of division problems don't have "natural" answers. This is why we invented first the long division algorithm (for decimal systems!), and later was a good reason to carry a slide rule (decimal again), and eventually calculators.

[Carlos Alvarez]

It's easy to split up a foot three ways. The original point you responded to was that base 12 is more flexible and obvious.

[Matt Mattingley]

My career in tech has always been about getting people to stop holding on to old "requirements." The way it goes is that you propose a new way to solve the problem, and the users give you a long list of reasons it won't work, mostly because they get hung up on doing all the old detailed steps as if THEY were the requirements. A guy working in metric would never build 3/4" dados; he'd make them 19mm. Sure, that's "the same" and they can often interchange also, but that's not the point. A lot of my builds have no specific number. I just finished a build where I absolutely cannot tell you a single dimension. I just ran down the cutting tools until I got a consistent set of pieces for the look I wanted. Is it metric or SAE? i’ve tried that a couple times and this is how it turns out. LOL

385477 385478

[Carlos Alvarez]

i’ve tried that a couple times and this is how it turns out. LOL



That is really cool and I bet it took a huge amount of math to make it work out. Boxes are easy.

[Glen Gunderson]

It's easy to split up a foot three ways. The original point you responded to was that base 12 is more flexible and obvious.

I've done a lot of woodworking and cabinetmaking and I have yet to run into a situation where the ability to divide base 6 math into smaller increments easily provided any kind of meaningful advantage. I mean sure, if you're making a 60" long cabinet you can quickly divide it into three 20" doors, four 15" doors, or five 12" doors, but once you have to account for overlays, gaps, and reveals that simplicity goes right out the window. And if actual precision isn't required (as it wouldn't be with rough math like deciding on three 20" doors for a 60" cabinet), dividing base 10 numbers is just as easy. A similar sized 1.5m long cabinet could have three 500mm doors, four 375mm doors, or five 300mm doors. And of course the same would apply to a 15" length you're dividing up into 5.00", 3.75", and 3.00" increments.

[Steve Demuth]

It's easy to split up a foot three ways. The original point you responded to was that base 12 is more flexible and obvious.

But we don't use base 12, do we? We actually use base ten when counting whole inches and base 10 representations of binary fractions for fractional inches, then augment that with an arbitrary new unit called a foot that is 12 inches. But that 12 is useful in exactly one situation: dividing a whole number of feet into 3 fractions denominated in inches. For any other division problem in American units, you are dealing with a combination of base 2 and base 10 (if you stick with inches), or base 2, base 10, AND base 12 (if you go with inches and feet).

So, let's take a real problem with an actual measurement: what's 1/3 of 3 feet 11 5/8 inches? There you have base 12, base 10, and binary fractions expressed as decimal numbers all in the same problem.

I use binary fractional inches and decimal whole inches all the time. I have no issue with them. I can do the above in a few seconds if need be. But no way in any rational universe it is a more sensible system than metric (in which the above measurement would likely be read as 120.95mm, or maybe 121mm, and I could do the division by 3, or 5, or even 7 in a blink.

Personally, I'm comfortable with either system, as long as we're dealing with household lengths. American is far whackier for longer lengths (yards, rods and miles) and with volumes than metric, though, and if you're doing anything that goes beyond those simple things to deal with energy, power, pressure ... there is no comparison. Metric / SI is just saner.

[Frank Drackman]

I also spent many years in the tech field and much of my time trying to people to understand that there were different ways to solve problems instead of simply automating a manual task. They had a difficult time trying to get their head around the idea of focusing on the end goal instead of the steps to achieve the goal.

[Bill Jobe]

Then there's axe handles.
My dad used that from time to time and I recall sitting in our parked car with him one day on a busy city street. He was looking at a lady walking down the sidewalk. Says:" That must be sixteen axe handles across the beam........"

Over the line?

[Steve Demuth]

Then there's axe handles.
My dad used that from time to time and I recall sitting in our parked car with him one day on a busy city street. He was looking at a lady walking down the sidewalk. Says:" That must be sixteen axe handles across the beam........"

Over the line?

My old man thought, at least with respect to land measurement, in rods. A rod is 16 1/2 feet, which is an absurd measurement, but which is equal to 1 / 160th of half a mile, which means that a strip of land 1 rod wide in a quarter section (which is 1/2 mile square) is an acre. Alternatively, one acre = 160 square rods. A furlong is 40 rods, so a square furlong is 10 acres.

So, in the English system, you had 12 inches to a foot, 3 feet to a yard, 5 1/2 yards to a rod, 40 rods to a furlong, and 8 furlongs to a mile. Nothing confusing about that.

[Matt Mattingley]

Some odd facts about the imperial system


https://www.youtube.com/watch?v=r7x-RGfd0Yk

[Chris Parks]

My old man thought, at least with respect to land measurement, in rods. A rod is 16 1/2 feet, which is an absurd measurement, but which is equal to 1 / 160th of half a mile, which means that a strip of land 1 rod wide in a quarter section (which is 1/2 mile square) is an acre. Alternatively, one acre = 160 square rods. A furlong is 40 rods, so a square furlong is 10 acres.

So, in the English system, you had 12 inches to a foot, 3 feet to a yard, 5 1/2 yards to a rod, and 40 rods to a furlong, and furlongs to a mile. Nothing confusing about that.

And don't forget the perch.

[Chris Parks]

I came across this in my YT feed which I found interesting, the US is a signatory to the metric system......


https://www.youtube.com/watch?v=SmSJXC6_qQ8

[Rod Sheridan]

Yes, the US has used metric standards for ages now.........Makes sense however...........Regards, Rod.

[Robert Engel]

Imperial only because its ingrained in my brain.

Metric when i need to divide or space something out ;-)

[Marshall Harrison]

I can't seem to visualize metric lengths. Tell me something is 6" and I get it but I can't relate 152mm to how big that actually is.

I think mm would be amore accurate and I have considered changing but I just can get a grasp on how big.small something is when stated in millimeters.

[Leo Graywacz]

It's easier to split 10" three ways? The closest you'll get on most inch rules is 3 11/32" - but very few woodworkers could do that quickly and easily in their head.

So, quickly now, divide a foot five ways in fractional inches.

My point is that in any system of measurement lots of division problems don't have "natural" answers. This is why we invented first the long division algorithm (for decimal systems!), and later was a good reason to carry a slide rule (decimal again), and eventually calculators.

I don't need to do it in my head. I take my rule and put the hook on one edge and angle the rule down to the 15" mark on the other edge. Then I just put ticks at the 3" marks. Now it's divided in 5 equal spaces and no math was required.

[William Adams]

It's easier to split 10" three ways?

Yes, 3 and 1/3rd inches --- 1/3rd of an inch is 24 points, so I'd go and get a DTP (PostScript) points ruler and use that.

[Jim Becker]

I can't seem to visualize metric lengths. Tell me something is 6" and I get it but I can't relate 152mm to how big that actually is.

I think mm would be amore accurate and I have considered changing but I just can get a grasp on how big.small something is when stated in millimeters.
I think this is probably the biggest barrier to many folks with adopting metric...our minds. Many of us in the US grew up without metric in mind or in learning. That said, I'm slowly but surely overcoming that by actually using the system. And I really like it. So my singular recommendation for anyone wanting to switch to another measurement scale is to commit to it and actually use it for a period of time, even if there are some struggles. Do it because you want to, not because someone else did it.

[Carlos Alvarez]

That's my problem with middle sizes in metric. I can easily visualize 10mm because I use metric hand tools a lot. I can easily visualize a meter because it's basically a yard plus a bit. I can easily visualize a kilometer, which is just over half a mile. I cannot even begin to visualize 152mm. The best I can do is convert it in my head and see that it's six inches.

[William Adams]

The thing is, I've actually been trying to use metric for all my CNC stuff, but haven't had any luck in finding out what the customary measurement units are, nor the specifics of metric versions of formulas, nor any endmill vendors who specify chiploads in metric.

https://sawmillcreek.org/showthread.php?264382-Metric-units-and-formulas-for-machining

[Steve Demuth]

Leo,

That's a great technique if the board you're trying to mark is at least 9" wide. Try it on a 3" wide board, or better yet, try to divide an 8' by 4' sheet of ply that way, and let me know how it goes.

[Steve Demuth]

Yes, 3 and 1/3rd inches --- 1/3rd of an inch is 24 points, so I'd go and get a DTP (PostScript) points ruler and use that.

:)

There must be some English measurement system that works for any fractional base, eh? Wonder where we go for 7ths?

[William Adams]

For 7ths I'd use Leo's technique --- if need be, using the PostScript points ruler on a small part.

[Steve Demuth]

For 7ths I'd use Leo's technique --- if need be, using the PostScript points ruler on a small part.

To each his or her own methods. If it works for you, that's what matters. But again, that technique only works if the piece you want divide has a fairly balanced length/ width ratio. To divide a 10" board into sevenths using 14" as your scale, you need to be just shy of square to land that 14" hypotenuse. It would work for relatively few divisions in my shop.

[Glen Gunderson]

Never mind the fact that metric is even more compatible with that trick because it's all whole numbers. Need to divide 120mm into 1/5ths and don't want to do the math of 24mm x 5? You don't need to go all the way up to 150mm (assuming your board can even handle a hypotenuse that's 25% longer than its length) when you can just angle your rule to 125mm and mark every 25mm. Need to divide 127mm into 7? Move up to 140mm and mark every 20mm.

[Matt Mattingley]

To stir things up a little more, when I started out I was taught degrees minutes and seconds as primary measuring for all angles.

About 15-20 years ago, everything started changing to decimals of degree. One of my math teachers said a heptagon (7 equal angles) is 51° 25’ 40”8 (Or 51° 25 minutes 42.8 seconds) or 51.42857°

So, do you like using degrees minutes and seconds or do you like using degrees a decimal?

And sure there is the metric radian(which is another ball of wax)

[Bill Jobe]

Didn't notice it mentioned. The firkin.

[glenn bradley]

Wow, over 90 posts. No wonder we can't decide :D

[Charles Taylor]

To stir things up a little more, when I started out I was taught degrees minutes and seconds as primary measuring for all angles.

About 15-20 years ago, everything started changing to decimals of degree. One of my math teachers said a heptagon (7 equal angles) is 51° 25’ 40”8 (Or 51° 25 minutes 42.8 seconds) or 51.42857°

So, do you like using degrees minutes and seconds or do you like using degrees a decimal?

And sure there is the metric radian(which is another ball of wax)


We could go 'round and 'round on this.

In the workshop, I use degrees and tenths. Arc second precision is beyond my abilities, and besides, any tools or instruments I have in the shop that can report fractions of degrees use tenths or hundredths.

Back at my high school & college job with a land surveyor, we expressed bearings and angles in degrees, minutes, and seconds...but there were conversions to and from decimal degrees to do the computations.

In my software career I know that the math libraries use radians, but values may be accepted and output in any number of units--radians, degrees (with three or four different ways to describe the fractional portion), mils, "semicircles", etc.

I think in degrees or radians, as the problem dictates. (In my workshop, there is never a problem that calls for radians.)

[Jim Becker]

Wow, over 90 posts. No wonder we can't decide :D

It's unlikely there will be a consensus anytime soon in this forum on what is a very subjective thing. :) But I think that most would be fine with the idea that for personal work, it doesn't matter what measurement scale one uses as long as they are consistent and committed to it. I think that most would also agree that for collaborative efforts, one system needs to be embraced for the project...mixing measurement systems at the same time can be, um..."interesting". ;)

I will make a personal speculation that at some point in time, metric will gain more visible hold in the US since it's already deeply embedded in industry and science and has been for a long time. (Relevant to woodworking, I went to make an adjustment on my US-manufactured CNC machine yesterday and note that all the fasteners are metric) There will still be personal resistance, but I think it's inevitable that the global community will actually come together on this. It may not be in many of our lifetimes, but...I think it will happen.

[Steve Demuth]

So, do you like using degrees minutes and seconds or do you like using degrees a decimal?

And sure there is the metric radian(which is another ball of wax)

I think in radians pretty automatically, but they are not really metric, even though the are by far the most common alternative to degrees - radians are the mathematically "natural" way to think about angle measurements, and thus what is used in nearly all scientific calculations. Gradians - the "metric" unit of angle that the French tried to foist on the world along with the decimal week, and meter, never caught a great following. The only person I've ever known to insist on them was a French software engineer with a military background. Everybody else I've ever had occasion to discuss the issue with, used degrees as we do.

[Matt Mattingley]

I think in radians pretty automatically, but they are not really metric, even though the are by far the most common alternative to degrees - radians are the mathematically "natural" way to think about angle measurements, and thus what is used in nearly all scientific calculations. Gradians - the "metric" unit of angle that the French tried to foist on the world along with the decimal week, and meter, never caught a great following. The only person I've ever known to insist on them was a French software engineer with a military background. Everybody else I've ever had occasion to discuss the issue with, used degrees as we do. and this is my problem. Sin coefficient of 45° is .7071.... A lot of calculations and conversions have been put to bed since 1986. 86 was the biggest poopsy year that ever had to be recovered from.

[John Gulick]

We are creatures of habit. I don't think the US will ever change.

[Chris Parks]

We are creatures of habit. I don't think the US will ever change.

Whether you want to admit it or not it has already started and big industry has already done.

[Bill Jobe]

We are creatures of habit. I don't think the US will ever change.

But she'd better be light on her feet. (or is that foot.
Nah. That's eons away. Or, 6yards.

"A product of Midwest shcooling."

[Mike Kreinhop]

Sin coefficient of 45° is .7071....

You would receive an eraser at full speed from one of my math professors for not writing "sine". As she would say, a sine without an "e" is just a sin. "SinX" is good, the "sine of x" is good, the "sin of x" is an invitation to be a target of her accurate and painful chalkboard missiles. :D

[Mike Kreinhop]

My unit of measurement at work and home is metric. After being stationed in Germany for almost 21 years, accepting the metric system was not optional. Our architectural and engineering drawings from U.S. sources must be metric, as components that make up or go into our facilities must be locally sourced. In my own shop, everything is metric.

The transition from Imperial to Metric was easy, but I don't remember when the transition was complete. When I'm back in the U.S., I have to mentally convert inches to millimeters when I'm looking at tools or hardware.

[Curt Harms]

That's my problem with middle sizes in metric. I can easily visualize 10mm because I use metric hand tools a lot. I can easily visualize a meter because it's basically a yard plus a bit. I can easily visualize a kilometer, which is just over half a mile. I cannot even begin to visualize 152mm. The best I can do is convert it in my head and see that it's six inches.

If I figure 300 mm = 1 foot (close enough), 150 mm = 6" 75 mm = 3" etc. etc. But yeah, unless we use it every day it's not going to "feel natural".

[Halgeir Wold]

I've been working in an environment where metric and imperial goes hand in hand... By occupaion I'm an EE, and grew up with binary, octal and hexadecimal..:rolleyes:

[John K Jordan]

...and grew up with binary, octal and hexadecimal..:rolleyes:

High 00000101. I was immersed starting about $2F years ago.

JKJ

[Rob Luter]

Decimal Inch. Almost 40 years of Engineering work has burned it deep into my head.