Metric v. Standard measurement usage survey / ?

[Jamie Schmitz]

So I am wondering if any Creekers have switched to metric from a standard measuring system while in the process of learning woodworking. To me the metric system seems more user friendly when it comes to woodworking just given the fact that it is lineal as opposed to fractional.

Of course this would be a moot question if you can convert fractions to decimals on the fly.

[Rich Engelhardt]

How about neither and both?
I use a story stick and/or pinch sticks as much if not more.
For small stuff, under 1", I use mostly fractional.

[ray hampton]

So I am wondering if any Creekers have switched to metric from a standard measuring system while in the process of learning woodworking. To me the metric system seems more user friendly when it comes to woodworking just given the fact that it is lineal as opposed to fractional.

Of course this would be a moot question if you can convert fractions to decimals on the fly.
housefly or horsefly ?
standard until I die then you can use what ever

[Jim German]

I agree that it seems like a decimal system would be easier to use. I still use fractions though.

[Greg Portland]

How about neither and both?
I use a story stick and/or pinch sticks as much if not more.
For small stuff, under 1", I use mostly fractional.

+1, I try to avoid measuring anything. When I'm forced to reach for a ruler I use metric.

[Peter J Lee]

I use both. I wouldn't mine using all metric, but I've still got tools that are imperial and a lot of materials come that way.

[Jeff Duncan]

I use both, metric for the CNC boring machine, and standard for everything else. I actually find metric to be OK for smaller measurements, and less so after a couple feet. This is one of those things where you get used to a system and it's hard to change.

I rarely have to convert fractions to decimals though....not difficult to do, but really not something I do often except for comparing metric stuff to fractional stuff.

good luck,
JeffD

[Peter Bell]

Because I live in Australia I have to ask the reason for this question. We use the metric system here, but occassionaly with imported items especially from the States they come in Imperial sizes.

Are you guys changing to the metric system? I believe it is best to stay on one measuring system per project. Unfortunately, here, especially if you are repairing old furniture you have to be aware of old systems because your measurements could be out.

I have seen it is advisable when starting a project to use the same tape measure throughout the whole project. Otherwise small errors might creep in. We get odd sizes when we use imported ply and materials, sometimes they measurements are just convereted to the system used in the Country importing. So\, it is an approx. appears close enough, is good enough for these guys unless you are at the end of the line and have to work around the small measurement discrepecies.

Pete

[mickey cassiba]

Coming from a surveying and then machining background, I use decimal inch, and decimal foot in my personal work. I am proficient in metric calculation('cept volume)but i'll be a foot and inch guy 'til I die.

[Van Huskey]

I use Imperial since well it sounds so regal and thus must be better right? Seriously, most everything I have is marked in imperial only and nothing is decimal imperial so I work in fractions.

[ian maybury]

I use both. We were imperial here (ireland) when i was a kid, and a lot of my early engineering and woodworking experience was imperial - but the country switched to metric in my teens and my engineering education was metric. I have some inch equipment like Incra positioners and work comfortably enough in both - although since they now have metric conversion kits available i might yet go that route.

Decimal inches are just as convenient as metric, i find most woodworking size dimensions easier to remember in inches than mm. It's when it heads off into small fractions (29/64ths and the like :)) that i struggle a bit as i never used them enough to get fully intuitive. It's awkward to assign tolerances to fractional dimensions too.

The US insistence on imperial is in one way a bit unlikely viewed from over here (very understandable in another) - in that the UK long since went officially metric.

There's still scope for funnies. To my knowledge in engineering and technical fields in general everything is dimensioned in mm. Yet our entire primary school system has based on some vagary headed off into teaching kids to use cms. No idea why, other than maybe that it keeps the numbers smaller.

ian

[Leo Passant]

This subject always makes me chuckle. The metric system is the standard system throughout the world... except in the US and Liberia! The US doesn't even use the superior British Imperial system (http://en.wikipedia.org/wiki/Imperial_units), but the much older United States Customary Units (http://en.wikipedia.org/wiki/United_States_customary_units).

For woodworking I use the metric system... you just keep counting single units (millimetres) without having to worry about convertions or decimal points. Usually the only drawback is if you can't count to 100.

[keith micinski]

What's Metric??

[Mark Ashmeade]

So I am wondering if any Creekers have switched to metric from a standard measuring system while in the process of learning woodworking. To me the metric system seems more user friendly when it comes to woodworking just given the fact that it is lineal as opposed to fractional.

Of course this would be a moot question if you can convert fractions to decimals on the fly.

Interestingly loaded question! "Switching to metric" from a "standard measuring system" implies several things:

a) That you started out using something other than metric, and switched. I'd have preferred to start in metric, but American market machines are not calibrated thusly.
b) That metric is something other than standard. It is most definitely standard in most of the world.

I learned both systems at school (UK, 70s). Today they learn the metric system, with Imperial as an afterthought.

However, I think that units of mm are insufficiently fine. A millimetre is about a 25th of an inch. Would suffice for most things, but not, for example, getting the width of a dado correct. Thus you're into fractional millimeters, and that's the same math minefield as Imperial. Half a mm? Quarter of a mm? Tenth?

May as well just use inches, because that's what all my equipment is marked in. I can "think" in both, but tend to use Imperial.

[Leo Passant]

However, I think that units of mm are insufficiently fine. A millimetre is about a 25th of an inch. Would suffice for most things, but not, for example, getting the width of a dado correct. Thus you're into fractional millimeters, and that's the same math minefield as Imperial. Half a mm? Quarter of a mm? Tenth?
Why complicate matters with fractions? That's just going backwards. For the occasions you want to measure something less than 1mm, all you have to do is move the decimal point.

[Rod Sheridan]

Canada went metric in the seventies, so science for me is metric, as is road speed, fuel volumes etc.

In woodworking however I was using Imperial and metric, then I decided to learn the 32mm system for cabinet making. That's when I realised how convenient it was to use metric and not have fractions.

This was very obvious when designing stuff, and I then decided to go metric for all my wood working.

Who can tell if a rail is 3/4" or 19mm or even better, stop converting and make your rails a nice round 20mm........Same for legs, instead of 2 inch use 50mm......On and on.

When I bought my new planer I had to specify mm or inch gauge so I went metric...............And as for whether plywood is metric or imperial, it's neither.

It actually is metric in thickness in North America (has been for a long time as the Plywood Manufacturers in NA went metric), however it's plywood so it's 19mm plus or minus whatever. Doesn't matter what you measure for a dado, it will need shims and different sheets are actually different.

So, make me a metric enthusiast...............Rod.

[Lex Boegen]

I'm comfortable with the metric system, but the vast majority of my tools are Imperial (USA) in dimensions. I do have a metric tape measure, but my drill bits, saw blades, Incra LS-17 fence, table saw rip fence scale, etc. are all Imperial, so that's what I generally use. Many times I wished that I'd wake up one morning and discover that Imperial was all just a bad dream and everything in the USA was suddenly metric.

[ian maybury]

Some of the issue with the US changing i suspect is that while measures for basic applications are fine, it gets a bit more complicated if you have a large indigenous industry producing all sorts of engineered parts and products based on inches mostly for the domestic market. The market is so enormous that even if domestic manufacturing isn't what it was many overseas suppliers can still afford to gear up to suit.

There's something resistant about the US mind set too. I always remember being told as a young development engineer in the early 80s doing potato processing machinery for US markets to (a) make it look and ideally be twice as strong as it needs to be (without it costing anything extra to build, mind you), and (b) use nothing on it that can't be bought in a corner hardware in deepest Idaho or the like. Tracking down UNC fasteners in Dublin in the early 80s was a challenge...

The UK faced the same problem, but with a rapidly fading engineering sector and importing a lot from Europe - i suspect it would have been much harder for them to hold out.

Here in Ireland it's a non issue - we have almost no engineering industry, so we take whatever the norm is from outside..

ian

[Mark Ashmeade]

Why complicate matters with fractions? That's just going backwards. For the occasions you want to measure something less than 1mm, all you have to do is move the decimal point.

Well I have a rule that's 1/2mm calibrated, and a set of digital calipers that'll do 1/2mm, but other than that, I have nothing to measure 0.4mm with...

[William Adams]

Inches and feet --- metric always results in bizarre decimals when one needs to divide things into halves, fourths, or worse yet thirds or sixths (if need be I'll break out a Schaedler Rule for points / picas)

[Chris Tsutsui]

I think it's a government economic plan to make me have to buy all my sockets and wrenches in both metric and sae.

[Chris Parks]

Inches and feet --- metric always results in bizarre decimals when one needs to divide things into halves, fourths, or worse yet thirds or sixths (if need be I'll break out a Schaedler Rule for points / picas)

That's news to me as I have been using metric for over 30 years having converted from imperial. What is half of 29/64, is that not weird? Anyone who has experienced and used the imperial system would not willingly go back.

[Mark Ashmeade]

Anyone who has experienced and used the imperial system would not willingly go back.

Are you sure about that? ;)

[Pat Barry]

You can tell its the dead of winter when the annual metric vs english discussion thread begins. LOL

[Gregg Feldstone]

I use both, due to having several European tools, ie Festool, Bosch, etc. which are graduated with metric scales.
Why do metric rules never seem to come with graduations smaller than 1mm?

[rick sawyers]

I like the imperial because of the fact that an inch can be divided down in half andin half again (to a 16th or a 32nd on a tape measure) and all these fractions (denominators to be exact) are multiples of 4. 4 to me is the basis for the imperial system and a square has four sides. A square corner is 90 degrees. 4 times 2 is 8 which when divided into 360(which is the degrees in a circle) equals 45 which is the cut in degrees to make when you are putting together two pieces of wood to make a square corner.

I am only saying, that to me the imperial system emphasizes the multiples of 4 and relates to geometry (circles and squares) and that is more relative to woodworking for me. Making things proportionate is a skill I have gained over time and using numbers has been very important to learning this skill. Everyone develops their own system of thinking and using wood--I can only guess how metric figures this way.

Metric is based on 10s and is probably great for addition, but when you divide 1 centimeter in half you have 5mm. Divide that in half and you are either .25cm or 2.5 mm; divide in half again and it is an eighth of a cm or .125mm (or 1+1/8thmm); divide again and you have .0625cm or the equivalent of 1/16thcm or .625mm (or 5/8ths mm?)

Point is, as soon as you divide in half with metric, you are into fractions and might as well use any measuring system with anything for a unit. As I understand it, the imperial system is based on 1 inch divided in half which goes 1/2, 1/4 ,1/8, 1/16, 1/32, 1/64, etc. When I am designing things or laying things out this "scale" is very handy and I use it quite often. I don't use 1/10th or 1/5th of anything anymore than 1/7th or 1/9th etc. One third of a foot is 4 inches and that I use, but not as often is 1/2 or 1/4th.

This is my half-baked argument for using Imperial--intuitive division and multiples of 4.

[Mark Ashmeade]

A square corner is 90 degrees. 4 times 4 is 16 which when divided into 360(which is the degrees in a circle) equals 22.5 which is the cut in degrees to make when you are putting together two pieces of wood to make a square corner.


Agreed that 360/16=22.5. However, two pieces of wood with 22.5 deg cuts facing each other would give you a 45, no?

Years ago, I was in 16 Signal Regiment in Germany. Took my about a decade (i.e. well after I left!) to realize why the bar was called the "4 Square Club".

[Chris Parks]

Are you sure about that? ;)

Of course I am sure about it and anyone who is honest about it will tell you the same thing, it is a far easier task to calculate and measure in metric. Why anyone wants anything finer than 1mm when woodworking is a mystery, wood moves more than that when the humidity changes 5% says he tongue in cheek. Are you telling me that you have seriously used both systems and not just for a week but an extended period of time like a year maybe and then reverted to imperial? I have lived half my life, or just about, under both systems and talking to others in and around trades that require measuring no one would go back.

[Peter Bell]

This thread reminds me of my late father. When giving me a measurement it might end like this. it is 120 cms and half an inch.

I have a number of steel rulers in my shed. I grabbed one of them last week as I had to copy some plans onto timber. the plans were from the States and one measurement was for 10 1/4 inches.

No problem until I went to find the quarte mark on the rule, it did not have any. Most are divided up in 8.s or 1tth or 32 or even 64ths. Not this one , I had to count up the dividing lines and there was ten Now, i have neen seen a measurement written as 10 .25 inches for 101/4 inches.

but this steel rule is talking like that.

So the rule was part imperial and metric imperial. Remind me not to us the imperial side again.

Pete

[Curt Harms]

I've always worked in imperial but consider this: I have a span to divide into 6 equal parts. The span measures 5 3/8" or 137 mm. Which is easier/quicker? Cheap/cell phone calculators are allowed.

[Mark Ashmeade]

Of course I am sure about it and anyone who is honest about it will tell you the same thing, it is a far easier task to calculate and measure in metric. Why anyone wants anything finer than 1mm when woodworking is a mystery, wood moves more than that when the humidity changes 5% says he tongue in cheek. Are you telling me that you have seriously used both systems and not just for a week but an extended period of time like a year maybe and then reverted to imperial? I have lived half my life, or just about, under both systems and talking to others in and around trades that require measuring no one would go back.

I understand exactly what you meant, but you actually wrote was arse-about-face:


Anyone who has experienced and used the imperial system would not willingly go back.

Would not go back to Metric?

Actually I have gone back to Imperial, but not out of choice. I was happy with Metric when I lived in Europe, but my US tools are all calibrated in Imperial, and the supplies are all in Imperial, so it's more practical to use Imperial in the US. The key word is (un)"willingly".

[Von Bickley]

Never went Metric and I'm too old to start.....

[Stephen Cherry]

When my Starrett combination square wears out, I'll consider going metric.

[Cary Falk]

I deal with metric at work(micron, angstroms, mm, etc). Even though I am used to what 200mm and 300mm is, most of the measurements are so small that I couldn't tell you how big 57mm is. I am good with fractions and know a lot of the decimal equlivents so that is what I am sticking with. All of my tools are in imperial also.

[glenn bradley]

I use either but generally one or the other throughout an operation. The U.S. has had a few false starts on getting on the metric wagon and the result of those failures is the melting pot we live with today. I survived the "we're metric / we're not, use new math / just kidding, use old math, we're metric again / we're not" eras and so pretty much use whatever works.

[Ole Anderson]

Here in Michigan, the State department of transportation (MDOT) mandated metric on all of their plans some time ago. It worked for a couple of years then they abandoned it suddenly. I suspect too many errors from folks not having a gut feeling for metric dimensions and blowing decimal points. If you spend your life working with feet and inches or decimal feet, you know what a foot is and probably a meter, but 10 cm takes some thought if you don't work with it day in and day out. Then there is the issue that all of the legal descriptions for land parcels for the last hundred years have been in decimal feet and there is no way that all of those legal records will ever get converted to metric. So you have a lot that is 203.22 feet wide and you neighbor wants to buy a 3.22 meter sliver from you? On the other hand, it appears that the auto industry had made pretty much the full conversion to metric. at least based on my garage work over the last 10 or 15 years. There are a few exceptions such as 1/2" lug nuts and 5/16" battery terminal nuts and I am sure a few more.

I have tried metric in the shop a few times when I pick up a steel ruler with inches and mm, works ok.

[ray hampton]

If you buy import machines [yes you do know what I amm talking about ] you will need metric and imperial wrenches [sockets , open end, allen ] there is a THIRD GROUP that are being ignored the machinists who use a system of inches plus decimals , convert 5 inches 0.250 tolerances are + .0 minus .010 to metric

[Dan Schocke]

I find it hillarious that people consider the metric system to be more modern than US customary units, since both were first defined in the 18th century. Use whatever you like.... If your brain calculates in mm, then use mm. My brain knows fractional inches, so I use fractional inches. I've also spent a considerable amount of time working with SI units in engineering school (we used both SI and US systems) -- there are advantages and disadvantages to both, and some calculations are simpler with SI while others are simpler with US units. Whenever I run into a fellow American that tells me how superior the metric system is, I like to ask him his height and weight.... I have yet to have any of them respond in units of Newtons (or kg, for that matter) and centimeters.

For those of you in countries that made the big change to metric, was there not a big pushback? When I was an exchange student in France, they still had prices listed in both new and old francs -- 30 years after the currency had been adjusted. I know France made the conversion to metric long ago, but that showed me that Europeans are just as stubborn as Americans.

--Dan

[Jerome Hanby]

Color me stubborn. I still stand there by my cutting table and convert inches to millimeters in my head or just give up and eyeball it when I'm setting the depth of cut on my Festool track saw. I seem bound and determined not to commit to memory the metric settings needed for breaking down plywood <g>.

[Mark Ashmeade]

I find it hillarious that people consider the metric system to be more modern than US customary units, since both were first defined in the 18th century. Use whatever you like.... If your brain calculates in mm, then use mm. My brain knows fractional inches, so I use fractional inches. I've also spent a considerable amount of time working with SI units in engineering school (we used both SI and US systems) -- there are advantages and disadvantages to both, and some calculations are simpler with SI while others are simpler with US units. Whenever I run into a fellow American that tells me how superior the metric system is, I like to ask him his height and weight.... I have yet to have any of them respond in units of Newtons (or kg, for that matter) and centimeters.

For those of you in countries that made the big change to metric, was there not a big pushback? When I was an exchange student in France, they still had prices listed in both new and old francs -- 30 years after the currency had been adjusted. I know France made the conversion to metric long ago, but that showed me that Europeans are just as stubborn as Americans.

--Dan

I think it's considerably older than that for Imperial units. 7th century English uses inches, (that's 7th, not 17th), it was only more formal definitions in the 18th and 19th centuries, as "technology" got better. Same for miles, commonly referred to over 500 years ago. Metres are indeed comparatively recent though, there was a definite drive to replace other (possibly "corrupt") units after the 1789 Storming of the Bastille.

[Halgeir Wold]

Right - some of you are REALLY stubborn.... :D
It's all really about what you are used to.... because there's probably not very large advantages to one over the other, if you look really carefully. I think, but I'm not certain, that there is a majority in the world for metric, but even for the "metricated" countries, there was and still are mix-ups, particularly when you cross from one trade to another. Science is today metric, by definition, standardized by the SI system.
Here in Norway, plumbing and carpentry was imperial, up until the late 60's mostly. People my age ( late 50s) still build with 2x4s, and use 1/2 or 3/4" garden hoses and have 4" main sewers in our houses, although we know perfectly well that the 2x4s are 46x92mm and the sewer line is 110mm......
My late father was a plumber by trade, and in my younger days I sometimes had to be his runner boy , - he really tried to teach me all about using 3/4" fittings for 1/2 pipes (or was it the other way), to no avail. During the last 20-30 years, pipe dim's throughout most of europe has gone metric, but it's still a rather lovely and confusing mess of imperial and metric.
I've been in science engineering for all of my professional life, and aeronatics use feet, miles and knots, meterology uses millibars, mmHg and meters, wind speeds are still in knots, miles/h, merters/second etc, navy uses meters,feets and knots, - and so on and so on, although most of these units are used in a metric fashion.
I'm an EE by profession, and most (but not all) of our components are measured in 100's of inches, as do most of the EE-CAD packages used in electronics for e.g. PCB layouts....
Countries HAVE changed, but the turnover mostly takes a couple of generations to settle in.
It's all about what are used to, and what you are willing to learn out of necessity or interest. There's really no big deal to it.....

[Dan Schocke]

The roots of Imperial units are definitely very old, but the US Customary units were defined in the 18th century, same as the metric system. Before then terms like "foot" or "gallon" referred to many different units depending on the trade or location using them (at least that's the way I understood it). The British Imperial system was defined in the 19th century, even though many of the terms go back way before then. All of the systems have had many updates to their definitions since that point, and none of them are really defined on any magical basis. All that really matters is that there is a standard that doesn't change very often. Conversion from one system to another is easy enough to do if you find yourself in that situation.

[Stew Hagerty]

Metric System...Hmmm. Wasn't that something we had to learn in school during the 70's because everything was going to switch over to it any day?

Yeah, that happened...

Seriously, the only time I use metric is when I have to look up a conversion for it.

[ian maybury]

I guess units are much like many issues in human endeavour. The benefit often comes come from just agreeing something and getting on with it. As ever the louder the protestations in favour of one or the other the less likely it is that this benefit will be delivered - and we seem to get very loud on this particular issue....

It's a lot mind you like lots of other basic skills too though. It seems that we never develop quite the same ease with those we learn later in life.

ian

[William Adams]

Half of 29/64ths would be 29/128ths. Simple, no?

5 and three-eighths inches divided into sixths would be 64 and one-half points.

By way of contrast, 136.525 mm divided into sixths would be ~22.754 mm and 137 mm / 6 == 22.8335 mm which are exactly the sort of thing I'm complaining about.

It drives me to distraction at work when a column gutter and two columns in a three column layout don't add up to a sensible number which can be easily communicated and used to make an ad which can be placed accurately.

[Halgeir Wold]

Maybe - if you changed your page size to metric tabloid, it would be a lot easier... ? :rolleyes:
WHich just proves my 10c's.... we either stick to what we are used to, or adapt to what we have to.. or find other work....
Those of us who have to, are well versed in working in microns when we have to, or Angstroms or nanometers, for that matter.. mil's is really no problem either - it's just a set of convertion factors embedded in the minds of those who need them, - or want them....no problem... but plain oldfashioned stubborness is one of the excuses I'll never accept from my crew collaborators or collegues - in a professional capacity, that is ... :cool:

[rick sawyers]

Yeah I got a little carried away with the math...

[William Adams]

The metric pages in question _are_ A4 --- the problem is it's harder to make a 3-column layout w/ nice margins and have all the numbers come out even in metric than it is when using points, picas and inches. This will remain true until there are readily available rulers w/ 1/3rd cm measures.

Sure, I could spec everything in integer scaled points (1/65,535th of an inch) but only TeX users use those.

[Martin C Wells]

I use both. I have metric and inch scales and tapes and the digital height gage switches back and forth, so what's the problem ?

[Jim Becker]

I will admit that eschewing inches and fractions for metric isn't an easy transition, since the former has been beaten into my head since early childhood. That said, my shop supports both measurement scales on my largely Euro machinery and I have rules and tapes that support both, too. But I also work a lot like Rich Engelhardt mentions in post #2 of this thread...story sticks and so forth get good action in my shop for nearly all real fitting work. I have only done one project so far "completely in metric", and will likely try to do that more when the opportunity avails itself. In fact, my tack trunks may avail themselves of that quite nicely.

[Mike Henderson]

I've used both. Metric is much easier and less error prone.

Mike

[Lloyd Kerry]

I grew up with the metric system, but still do all my woodworking in imperial. When I did field work for the dept. of agriculture, I constantly had to switch back and forth between acres and hectares, kilos and pounds, etc. Made my brain pretty sharp.
All my pouches are available in either system. ;)

[Chris Parks]

I understand exactly what you meant, but you actually wrote was arse-about-face:



Would not go back to Metric?

Actually I have gone back to Imperial, but not out of choice. I was happy with Metric when I lived in Europe, but my US tools are all calibrated in Imperial, and the supplies are all in Imperial, so it's more practical to use Imperial in the US. The key word is (un)"willingly".

I am on night shift and writing stuff at 4am leads to arse about face. If I recall correctly the auto industry wanted the US to go metric or they would do it themselves and on their own. Are all domestic cars metric? I think the US has a fairly large use of metric without realising it and this will grow over a long period of time to the point where the mandated change won't be too much of an issue. It has already started without anyone realising it, you have people in this thread who are using metric due to have machines that require it and they don't exactly hate the system.

It strikes me odd that the US on one hand led the world in a metric system (money) and those that use those that use that system daily can't see the advantage of using it in measurement. When Australia first converted to a metric money format it was hilarious as no one could figure out what anything was worth and we all mentally converted back to pounds, shillings & pence for about two weeks until we got used to it.

[scott vroom]

You mean 10 inches doesn't equal 10 millimeters?? Crap, no wonder nothing fits.

[Kevin W Johnson]

I wonder what the current cost of switching in th US would be nowadays. Roadsigns and text books alone would be immense, not only in cost of materials, but also in man hours making the switch.

[Mike Davis NC]

I mostly work in pixels at my job, I do Jacquard design and one pixel on the computer equals one crossing of threads in the cloth.

In everything else I don't care, I can use what ever is handy. I like dividers for wood working.

I remember when they first decided to change in the US. They made a fatal mistake in the process. Instead of just showing a metric stick and saying "here is a meter, it is divided into ten parts and each of those are divided into ten parts" Easy right? Well no, they had to come out with 25.4 and 2.2 and 1.9 and all kinds of crazy conversions that no child in grade school could remember. And they went home and told their parents how horrible it was and so it was over before it got started.

I taught my kids to estimate measurements when they were 3-4 years old. I would hold stuff up and ask "how long is this?" sometimes I would ask How many mm and sometimes I would ask how many inches? They learned to use either or both it doesn't matter and no conversions. If you want to know metric use a metric rule if you want to know inches use an inch ruler. keep it simple.

[Rich Engelhardt]

So, how does everyone deal with plans and stuff that use a different system?
I'm not sure I want to convert inches to mm or vice versa.
If the plans are in inches, that's what I use.
If the plans are metric, then that's what I use.

W/plywood thses days being mostly a mystery as to what it's supposed to be, then I use who knows what.
I hate to say it, but, that's one really nice thing about MDF. If it says it's 3/4", then it's 3/4". Not some undersized something or other or some mystery size.

@ Jim Becker - I have to give credit where it's due.
You're the one that got me started using story sticks and pinch sticks, etc.

[Curt Harms]

Half of 29/64ths would be 29/128ths. Simple, no?

5 and three-eighths inches divided into sixths would be 64 and one-half points.

By way of contrast, 136.525 mm divided into sixths would be ~22.754 mm and 137 mm / 6 == 22.8335 mm which are exactly the sort of thing I'm complaining about.

It drives me to distraction at work when a column gutter and two columns in a three column layout don't add up to a sensible number which can be easily communicated and used to make an ad which can be placed accurately.

My pencil lead is not that fine :). 23 mm would be perfectly adequate in most non-precision (think 0.0005" tolerance) applications I think.

[Kent A Bathurst]

I use imperial, but mostly I use "tick marks".

My Starrett dial calipers have tick marks that are exactly aligned with the tick marks on the venerable PC690 depth wheel which are exactly aligned with the tick marks on my rip fence which are exactly aligned wit the tick marks on my......................

You get the point............

[Rick Thom]

So, how does everyone deal with plans and stuff that use a different system?
I'm not sure I want to convert inches to mm or vice versa.
If the plans are in inches, that's what I use.
If the plans are metric, then that's what I use.

W/plywood thses days being mostly a mystery as to what it's supposed to be, then I use who knows what.
I hate to say it, but, that's one really nice thing about MDF. If it says it's 3/4", then it's 3/4". Not some undersized something or other or some mystery size.

@ Jim Becker - I have to give credit where it's due.
You're the one that got me started using story sticks and pinch sticks, etc.
There's the nub of the issue. You design and work in metric, not imperial, and there's no conversion required.

[Ronald Blue]

.23 mm is about .009 thousandths. .0005 or 1/2 thousandth is a pretty tight tolerance for all but ultra precision applications. Certainly nothing you would ever need when working with wood. I can adapt to either system although I grew up with the good old inch system. Most all autos are pretty well metric especially on engines but more and more frame hardware is as well. Industrial engines are mostly all metric these days as well. Cummins, Deere, Cat. I don't mind that but there was a time when they had some of both in use and that drives you nuts when they had both in use because you are using a metric socket on one thing and then you have a "standard" on something else. While I still encounter a little of this on accessory mounts etc. most things are metric. As many have said it's what you are used to. Both have served their purposes effectively. One thing I have always liked about metric is you don't need a tap drill chart for selecting the right drill bit. Just subtract the thread pitch from the diameter and you have it. I don't know if the inch system will disappear in my lifetime. I was here when the talk in the 70's of a mass conversion was going on but that just dissolved and here we are still using both.

[Steve Griffin]

Decimal inches works well for me.

It's hard to imagine a more worthless measurement increment than the millimeter for cabinets/construction. It's too small to pencil mark or read when taking a measurement. It's way too big for fine machine adjustments.

The 1/16 of an inch increment is about perfect for human marking and measuring.

Using decimal inches to the thousandth is the perfect increment for adjusting my wide belt sander. Doing math is easy with the decimal system, and when working with US clients using inches is the ONLY way to communicate with them.

I do all my plans/cutlists in decimal inches, and it takes about one project for a new employee to memorize the basics. Attached is a cheater sheet, which I have attached before.

The very best thing about the imperial system is it is different than metric, and I like being in a country which is different.

[Rod Sheridan]

So I am wondering if any Creekers have switched to metric from a standard measuring system while in the process of learning woodworking. To me the metric system seems more user friendly when it comes to woodworking just given the fact that it is lineal as opposed to fractional.

Of course this would be a moot question if you can convert fractions to decimals on the fly.

Jamie, your thread title makes me smile every time I read it, because metric is standard, Imperial is the odd ball in this world:D.

Regardless, I did post an answer however I failed to indicate that if I receive a drawing in a particular measurement system, I build it using that system. Conversion is a mess, so I would suggest you start by trying a project in metric, probably from plans you have drawn yourself.

Regards, Rod.

[Halgeir Wold]

It's hard to imagine a more worthless measurement increment than the millimeter for cabinets/construction. It's too small to pencil mark or read when taking a measurement. It's way too big for fine machine adjustments..
Strange thing to say - unless you really intend to be the oddball....
I do most of my work in millimeters - machine drawings at work, or personal woodwork or what-have-you. I've never had a problem to pencil mark to the millimeter. As for fine machine work - that's when we use tenths or hundreds of millimeters- and even thousands for high precision work. Oh sorry - that's in base 10, so it's metric. And BTW - 1/1000" is still just 0.0254 mm, so even high precision works better in metric.... :cool:




The very best thing about the imperial system is it is different than metric, and I like being in a country which is different.
Making claims of difference for the sake of difference itself is OK with me, but is hardly a signal of an open mind.....

As the previous poster just said - it is really imperial that is the oddball of the world these days, but I guess we'll have to live with two systems for still many years. I have personally no problems working with both. I also work for a company that has a lot of international contracts, so the necessity of learning conversion is just the way it is.
We have a major building renovation and extension project going on at work, roughly 1000 sqm- or 10.000 sq.ft, and some of my responsiblity is electric power and communication systems. All the drawings that pass my desk for inspection is in millimeters, and workers of all trades work to the same drawings - in millimeters - carpenters, plumbers,electricians, HVAC, etc.etc. No-one seems to have any problems reading the drawings. It's all in our minds... and an open mind usually functions better......:)

[Pat Barry]

Metric system works great for people in Europe and it should stay that way. The kids grow up accustomed to it over there and good for them. I use both for my job and rarely have any problems because certain types of work are customarily done that way and thats the way I was trained. But lets face it, American kids grow up learn the English system from their parents and thats the way it should be. Both systems work, but I never think of any daily tasks in metric. That would drive me crazy. Everything I do is in English system because thats what I learned early on and it works. The metric system is not easier or more convenient either. Furthermore, there is no reason to do things differently. I hope US never goes metric because it is pointless and has zero cost benefit to anyone.

Lastly, what is a meter anyway ? Wikipedia "Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole (at sea level), its definition has been periodically refined to reflect growing knowledge of metrology. Since 1983, it is defined as the length of the path travelled by light in vacuum in 1 ⁄ 299,792,458 of a second". Can I ask everyone why that makes any more sense than, lets say a foot or an inch?

Then there is the famous kilogram, which according to Wikipedia is "The kilogram (SI symbol: kg), also known as the kilo, is the base unit of mass in the and is defined as being almost exactly equal to the mass of one liter of water." What - not exactly? Just almost the same? What kind of nonsense is that? Of course it must make perfect sense that the kilogram is based on a liter right, because the liter is 1/1000 of a cubic meter and we all know how important it is to reference our daily life to the path travelled by light in vacuum in 1 ⁄ 299,792,458 of a second. Why not the path of light in vaccum in some metric-like base 10 period of time? Like, 1/1,000,000,000 second?

No, I'll stay with what I know, thank you, and continue to teach my kids and grandkids the same way I learned.

[Peter J Lee]

How are you going to explain what a mile or a pound is? Will you tell them about a thousand paces or 1,728 carob seeds?

[William Adams]

Curt Harms wrote:

>My pencil lead is not that fine :). 23 mm would be perfectly adequate
>in most non-precision (think 0.0005" tolerance) applications I think.

Except 23 mm x 6 == 138 mm so the assemblage will be too large by 1 mm or more.

[Halgeir Wold]

Some hundreds of years ago, the foot, the inch, the pound, and what-ever-have-you, were different from country to country, and as international trade expanded, this was the direct cause of severe aggravation between people and countries. It was also a serious source of fraud in trade. The metric system emanated within the french science academy around 1800 or so, to end this confusion of size and value differences. The SI system of scientific measuring units is of a lot more modern origin. The base of 10s was introduced to ease transitions and coversions, as opposed to the odd-ball systems of 12s, 20s and so on, that was common to other measurements and values. Strangely enough, most of what you call "Imperial" measures, is and have been metric for a very long time, except for measuremenths of length. - just look around. Even if I grew up as something of a math geek, and is used ot metric, I fail to see how odd-ball and uneven divisons are easier than multiplying or dividing by 10s, - in practice mostly simply moving the decimal point, or comma here in Europe. We still have a lot of different units for different values, and this is probably how it is going to stay for many years to come, but once you start shifting measurement values across borders, it is surely immensly easier to use comon standards. It is my bet,that unless the political narcissists of this modern world manages to finish us all of in one blow, in 100 years or so, even the US will be "metricated"... it is slowly sneaking up upon you without most of you not noticing, and have been for quite a while... :)

BTW - Pat - your definition of the meter is all wrong.... 1 meter= 1 650 763.73 wavelengths of light from a Krypton atom, elevated to the energy transistion level of 2p10 and 5d5 ( in practice by heating the stuff, so that it radiates light ).....

I do hope at least some of you realises that to some extent I have been pulling your legs, although not without serious intent, as I do find discussions like this quite amusing, but I have already stated my sincere opinion on this matter - it is really all in our minds. Most of us find it not being a problem at all.......... and we are all free to do as we choose.

[Pat Barry]

See, you just can't trust what you read on Wikipedia. LOL

[Pat Barry]

Lets go to WIkipedia for the answer "The exact length of the land mile varied slightly among English-speaking countries until an international agreement in 1959 established the yard as exactly 0.9144 metres, giving a mile of exactly 1,609.344 metres." OMG - miles ARE metric.

[James Carmichael]

metric from a standard measuring system.

Metric is the standard.

I just wish the U.S. could go all the way, I'm sick of having to have two sets of wrenches & sockets to work on things, even the same machine.

[Jamie Schmitz]

I gave in. http://www.wolframalpha.com/input/?i=137+mm+%C3%B7+6

[Mike Delyster]

Metric is the standard.

I just wish the U.S. could go all the way, I'm sick of having to have two sets of wrenches & sockets to work on things, even the same machine.

In Canada they switched the road signs to metric in the seventies. In 2012 we still work with pipe, fittings and flanges that are made all over the world and they are all made to imperial measurement sizes. We only have one set of wrenches at work " standard measurement".
At home I've got both sets of tools as you need both. Canada isn't even close to being all the way.

[William Adams]

Jamie Schmitz wrote:

>I gave in. http://www.wolframalpha.com/input/?i=137+mm+%C3%B7+6

Weird that the precision is so low there. As I noted previously dividing a 137 mm wide object into sixths gives a typically irrational decimal value of 22.8335 (according to Macromedia FreeHand --- and multiplying that by 6 or enlarging 600% restores the original 137 mm, which it shouldn't since the correct value is the irrational 22.833333333333333333333333333333 (w/ a line over the final 3)).

FWIW, the 1 mm error of rounding up to 23 mm is 0.03937" --- quite a bit more than the 0.0005" tolerance Curt Harms noted.

[Pat Keefe]

Australia went metric in 1966, but I was born in 1971. So I am conversant with both metric and "imperial" ( & SAE/Whitworth). I prefer metric, but to annoy some of the older members of the wood club I translate imperial measurements to metric 1/4" 6.35 mm, 3/8mm 9.8mm and so on. I can buy my timber by the "board foot" or "lineal meter", sheet goods "8 x4" or 2400 x 1200 (real size 2420 x 1220). Funnily enough, all my surfboards are measured in Imperial, I see a metric measurement for a board and ask the shop assistant what?

[Chris Parks]

I just tried to order a metric combination square blade from Amazon. I reckon America must be stockpiling them for when you guys change over as Amazon will not ship a metric blade or square to Oz but will ship imperial items. How damned silly is that!!!

[Curt Harms]

Curt Harms wrote:

>My pencil lead is not that fine :). 23 mm would be perfectly adequate
>in most non-precision (think 0.0005" tolerance) applications I think.

Except 23 mm x 6 == 138 mm so the assemblage will be too large by 1 mm or more.
1mm=~1/24", half way between 1/16" and 1/32". Sandpaper:).

[ray hampton]

1mm=~1/24", half way between 1/16" and 1/32". Sandpaper:).

so 1/24" is .048, we better buy extra magnify glasses
divide 1/24 in half and you will get 1/48 or 0.024

[Leo Passant]

A large percentage of US industry is already metric to compete on the global market. It's usually the DIY markets and hillbillies that offer resistance.

219875

[Jim German]

The US aerospace industry still uses imperial units, and thats unlikely to change anytime soon.

[Kevin W Johnson]

A large percentage of US industry is already metric to compete on the global market. It's usually the DIY markets and hillbillies that offer resistance.

219875


You know, I don't consider myself a hillbilly but I still find that comment to be an insult.

Edit: Ok, I really hope that was in good humor, but it reads in bad taste.

[Leo Passant]

You know, I don't consider myself a hillbilly but I still find that comment to be an insult. And I dare say that you have nothing to back up that assertion, other than your obvious prejudice.

I guess I forgot to add a smiley. :p

[Kevin W Johnson]

I guess I forgot to add a smiley. :p

Ok, I edited my previous response. I indeed hope it was meant in good humor, but it does read in very poor taste.

[Myk Rian]

I use Imperial, learned metric when repairing tools.

The US lost a Mars probe because it was built in Imperial, but metric was used for weight. Calculations got all screwed up, so it crashed/burned up.

[Curt Harms]

so 1/24" is .048, we better buy extra magnify glasses
divide 1/24 in half and you will get 1/48 or 0.024
And the finest pencil I have is .5mm or .019" or 19/1000". Of course there's a marking knife........ It just gets silly after while.

[Steve Griffin]

These threads always start out as "what measuring system for woodworking" and digress to "what measuring system should the US adopt if we can only have one".

I'm very fond of the metric system, and if we HAD to choose one I'd probably go for that.

But in woodworking, since we have a choice of systems still, it's a no brainer for me to use Standard. As mentioned, the 1/16 of an inch is a wonderful increment that can be easily read on a table saw fence, cutting jack studs and marking with pencil. What a pain it would be to sheetrock with a fat pencil and nothing but of blur of MM marks on your tape.

And if you do your math and plans in decimal inches, those cumbersome fractions go away.

And the 1/1000 increment is perfect size for machine set up and caliper use. 1/1000 of a MM is too small to care about, 1/100 is too big, and of course 1MM is the least useful increment of all. When using my belt sander, we yell out to each other --"take off 3 more" or take off 5 more" dropping the 1/1000 suffix.

So continue endless debating what system each nation state should adopt if you like, and but in this country and dealing with fellow americans, I'll choose and recommend standard for now.

[Don Morris]

When the US switches to driving on the left side of the road, I'll switch to metric.

[ray hampton]

before U S A switch to driving on the left side of the street, will they need to replace all of the cars with a left side steering wheel ?

[Van Huskey]

I guess I forgot to add a smiley. :p

Smileys can be important sometimes! :D

The thing that hit me when I read the post is the metric system is considered easier, by allowing "easier" math. My thought was you were unintentionally saying hillbillies had a higher aptitude due to their ability to manipulate imperial measurements.

[Curt Harms]

before U S A switch to driving on the left side of the street, will they need to replace all of the cars with a left side steering wheel ?
Nope:). U.S. Virgin Islands drive on the left side of the road but (most) vehicles have the controls on the left. Live there a while, get used to 'driving left' then come back to the U.S. It's real easy to make a turn into the wrong lane especially making left turns. Never bent any tin but got honked at a time or two.

[Nick Canzona]

This depends on many factors. It's handy to have both systems. The Imperial system has several variants, which make it somewhat more flexible: 1) Decimal feet, 2) Feet, Inches, Fractional Inches, 3) Inches, Fractional Inches, 4) Decimal Inches. All have their advantages. The metric system makes for easier arithmetic, compared to (Imperial) fractions, but there's no reason, other than habit, why decimal inches couldn't be used. These days, many specifications are in metric: appliance dimensions, hardware sizes, tooling, etc. It's often convenient to work with several systems simultaneously. I might buy dimension lumber by the foot (length) and inch (width), hardwood by the board-foot, plywood by the 4' x 8' sheet, then build 36" cabinets, in which I install metric (Euro system) drawer slides, and finish off the drawer fronts with 3-1/2" pulls. And I have to leave room for the 760mm appliance...

[johnny means]

I call my system Metriperial. It's sort of the Spanglish of measurement.

[Alan Wright]

I use inches exclusively until I use my digital calipers, which is when I have consult a conversion chart I have hanging on my wall in the shop. When I use my Domino, I have to consult the same chart to figure out what 5/8' is in metric....

[Rod Sheridan]

I use Imperial, learned metric when repairing tools.

The US lost a Mars probe because it was built in Imperial, but metric was used for weight. Calculations got all screwed up, so it crashed/burned up.

Yes, however I think the error was that the various teams didn't realise the system units were different, not that they couldn't have converted them properly.

Time to ditch the imperial system...........Rod.

[Kevin W Johnson]

Yes, however I think the error was that the various teams didn't realise the system units were different, not that they couldn't have converted them properly.

Time to ditch the imperial system...........Rod.

Time for those who think we should do so to pony up and pay for such a move. :D

[Tom Hammond]

Inches and fractions unless I'm doing sliding dovetails... then it's thousandths.

[Rod Sheridan]

Time for those who think we should do so to pony up and pay for such a move. :D

I already have, I had to buy some new measuring tools for my shop.:D

Regards, Rod.

P.S. Metric is less expensive and I can prove it.

[Joel Wesseling]

50 years old and use metric for projects that need to be accurate with less confusion for making calculations.
Imperial for rough measurements and basic construction

Metric is superior and can't understand why USA is not on board

[George Gyulatyan]

Here are my thoughts on this. I grew up in former USSR, so grew up with the Metric system. Moved to the US when I was 16 and have lived most of my life here, so in many cases Imperial feels more natural to me. For example, I usually have a better idea for the size of something when expressed in imprial units compared to metric. When measuring stuff, I also feel more comfortable with Imperial.

Where Metric shines and Imerial completely falls appart is when doing math at different scales. It is easy to do math with mm and km for example, just a matter of a decimal point.

Things aren't so simple when you have to do math that combines inches, feet, yards and miles. 12 inches = 1 foot, 3 feet = a yard... let me see... according to this app called "Units" on my iPhone 1,760 yards = 1 mile... Just the fact alone that I actually had to use an app to figure that one out is telling.

With metric, this conversion is a non-issue. 1km = 1000m, 1m = 100cm = 1000mm, etc.

[George Gyulatyan]

P.S. Metric is less expensive and I can prove it.
That's only because 1cm is smaller than 1 inch. Less material, less expense :D

[Kevin W Johnson]

I already have, I had to buy some new measuring tools for my shop.:D

Regards, Rod.

P.S. Metric is less expensive and I can prove it.

I'm referring to road signs, maps, text books, and most likely a long list of things that we use every day and don't give a second thought too.

[William Adams]

Where Metric shines and Imerial completely falls appart is when doing math at different scales. It is easy to do math with mm and km for example, just a matter of a decimal point.

Things aren't so simple when you have to do math that combines inches, feet, yards and miles. 12 inches = 1 foot, 3 feet = a yard... let me see... according to this app called "Units" on my iPhone 1,760 yards = 1 mile... Just the fact alone that I actually had to use an app to figure that one out is telling.

With metric, this conversion is a non-issue. 1km = 1000m, 1m = 100cm = 1000mm, etc.

With Imperial, one can do many scales which metric doesn't allow --- 1/12th, 1/32nd, 1/72nd, &c., and a decimal ruler makes 1/10th, 1/100th, &c. as easy as metric, but isn't really needed.

With metric one is limited to decimal scales and is SOL if for example 1/30th would be suitable and one needs the length of a 1 m element and one doesn't have the special rule needed to mark 3.3333333 cm --- by contrast 1/32nd of a yard is a neat / even division (1 and 1/8th and 1/36th 1" == 1 yard, is even easier).

A solid advantage metric has is enlarging / reducing B-series plans on a copier --- quite elegant w/ no wasted paper, but that doesn't make up for the solid grounding Imperial has in human experience /scale.

[George Gyulatyan]

With Imperial, one can do many scales which metric doesn't allow --- 1/12th, 1/32nd, 1/72nd, &c., and a decimal ruler makes 1/10th, 1/100th, &c. as easy as metric, but isn't really needed.

Which is one of the reasons why I said I feel more comfortable measuring stuff in Imperial. No need to be so defensive about Imperial. Both systems have their advantages and disadvantages. Once can use that to their advantage :)

[Halgeir Wold]

And what do you imperial guys do when you need a 20th, a 25th and so on - all the divisions that are a lot easier in metric?
5hts, 7ths and so on are equal buggers in all systems. It is easy to isolate cases that are easier in one system than the other, and both systems have their pro's and con's, but all the isolated cases that you concider pro imperial, - too small units or too large units ( which one is it ? :-) ) are of no concern to us metric guys - it's just a way of thinking..... what is certain, though, is that imperial is slowly loosing grounds due to international trade and technology exchange - except maybe in woodworking.... ( sorry guys - I couldn't resist ;) )

[William Adams]

And what do you imperial guys do when you need a 20th, a 25th and so on - all the divisions that are a lot easier in metric?
5hts, 7ths and so on are equal buggers in all systems. It is easy to isolate cases that are easier in one system than the other, and both systems have their pro's and con's, but all the isolated cases that you concider pro imperial, - too small units or too large units ( which one is it ? :-) ) are of no concern to us metric guys - it's just a way of thinking..... what is certain, though, is that imperial is slowly loosing grounds due to international trade and technology exchange - except maybe in woodworking.... ( sorry guys - I couldn't resist ;) )

20ths and 25ths would be done w/ the decimal inches ruler I mentioned in my post.

5ths are easy w/ a decimal ruler as well (and trivial of course w/ metrics --- not sure why you mentioned that).

Never had occasion to divide up into 7ths --- if I did, I'd make sure that the item in question started out at some integral of 7/64ths or such.

William

[Steve Hayles]

I personally prefer Imperial even though we are metric in Aust.

But I was taught Imperial so I guess I was lucky to be a child of the change over.

As mentioned before once you reach 1mm there's nowhere to go and often it is required that you have to plane as little as 128th/1" off a draw to make it fit precisely.

Having said that I also teach woodwork from my workshop and in most cases teach the metric method.

So for me it's Imperial for the Masses I use Metric.

And of course there's always the old favorite of ordering 3.6m of 2"x4"????


Cheers


Steve

[Halgeir Wold]

- and your 128th being 0,1984375 mm, -or by any practical means .2mm. Now you won't find a measuring stick or tape measure showing 10ths of a millimeter, any more than 128ths of an inch. For precision work, 10ths and 100s of the millimeter are all commmon, but usually not in woodworking, and I don't think 128s are common in the US either.
Most of the worlds precision work is done in 100s and 1000s of the millimeter.

and BTW- what is 3.6m ..??? -not happening to be 12' = 3.6576000000000004 m is it ?? :cool:

seriously guys , the only thing these two camps will ever agree upon - is to disagree. Just don't take it too serious .. :)

[Steve Hayles]

3.6m or 3.6 meters is approx 11.8ft or as near to 12' as the metrication experts could get it. Or for preciseness.

3.6 meter = 141.732 283 46 inch.

True there are no rulers I have found with 128th but mine do have 64ths. Which is more (or less?) than my metric ones.


Cheers


Steve

[Kevin W Johnson]

My guess is that most of the resistance is most likely due to the "everyone else in the world is on the metric standard" arguement. Which is an invalid arguement anyway. If the rest of the world started jumping off cliff's, is that an arguement to follow?

Simply put, whether the US "adopts" metric as an official standard doesn't matter at all. Imperical measurements will most likely live on forever anyway, at least in some form.

Use whatever standard fits your needs the best. I use the one that fits the task at hand. I even have a laminated chart in the shop that shows/converts fractions/decimal/mm for quick reference. Most all my drill bits, taps, and dies are in Imperial, so likewise is most of my bolt/machine screw collection.

[Pat Barry]

Can we please drop the term Imperial from this conversation? If you live in the USA, the proper term is US Customary units. Imperial is for the British Commonwealth. We weigh things in pounds, they use stones (whatever that is). Besides, the British Commonwealth has converted to metric. Thank you.

[Curt Harms]

My guess is that most of the resistance is most likely due to the "everyone else in the world is on the metric standard" arguement. Which is an invalid arguement anyway. If the rest of the world started jumping off cliff's, is that an arguement to follow?

Simply put, whether the US "adopts" metric as an official standard doesn't matter at all. Imperical measurements will most likely live on forever anyway, at least in some form.

Use whatever standard fits your needs the best. I use the one that fits the task at hand. I even have a laminated chart in the shop that shows/converts fractions/decimal/mm for quick reference. Most all my drill bits, taps, and dies are in Imperial, so likewise is most of my bolt/machine screw collection.

It's the 'most' that can be a real PITA. 6mm looks a lot like 1/4", 8 mm looks a lot like 5/16", 1/2" ~ 12 mm, 3/4" ~ 18 mm etc. etc. Why in the world won't this 5/16" nut go on this bolt?!? Uh, 'cause the bolt is 8 mm?

[Van Huskey]

While I find the OPs question interesting it is odd there is so much "argument" associated with it. In the US the vast majority of woodworking products from rules to wood are marked or sold in fractional inches. The metric system is often easier to convert from one unit to another but working with fractional inches isn't Diffy Qs, to my recollection I have never had to determine the Wronskian of two functions in the woodshop. Neither system is more accurate or precise, though a certain measuring tool may be. In the world of woodworking about the only conversion factor you need to know is 2.54 if you need to move from one to the other. Neither system is superior in any way except for one being easier to teach a child. Switching to all metric in the wood shop, in the US, causes more problems than it solves IMO.

[David Hostetler]

I use both metric and imperial measurements. Most of the scales on my equipment are in imperial units, and many of the projects I have been working on need to interface well with existing structures that are built using inches and feet... For example the cabinets I built for my shop needing to be hung off of studs that are 16" O.C. is a good example.

My table saw, and planer both have fractional scales, where my jointer has both fractional and metric scales.

Except plywood, the stock I buy is sold in fractional sizes....

I would like to update the scales on my equipment to do BOTH metric and fractional. My digital caliper does both...

I must admit, I grew up taking my shop classes and advanced mathematics classes in the 1980s, and they taught us to use both, I guess I learned well...