Gone metric?

[Dave Cav]

Anyone converted most of their operations to metric? I'm really getting tired of dealing with fractions, and one millimeter equaling about 1/25" seems plenty accurate enough.

[Mark e Kessler]

Yes, totally better and I spent the last 30yrs imperial.

The hardest part for me was visualizing the larger dimensions like say 3' sounds a bit silly but when I thought long and hard about it over several beers and weeks then realizing that 1' basically equals 305mm - boom, easy peasy...


Anyone converted most of their operations to metric? I'm really getting tired of dealing with fractions, and one millimeter equaling about 1/25" seems plenty accurate enough.

[Frederick Skelly]

Several people here have done so, in addition to our Canadian friends. The ones who have seem to like it.

(I tried to find the most recent discussion but failed. Maybe Mr Koepke will reply - his google-fu is better than mine.)

[roger wiegand]

I recently posted on my conversion. There have been a few hiccoughs and some things that are impractical to convert now (like all my drills and the mortising chisels for my mortiser), but mostly t has been smooth and easy. Life is better now, mostly for the cost of a few stick-on tapes for machines and a couple new rules. (The Tajima metric measuring tapes are wonderful)

I don't miss doing arithmetic with fractions at all. (yes, I can understand one could use digital inches, but almost nothing in the woodworking world comes marked that way)

Avoid doing conversions if at all possible, it is a huge source of error. Just work on training yourself to think only in metric. Soon 2.5 or 3 cm begins to look like the logical dimension for a board.

[Halgeir Wold]

On several occcations, I've been pulling peoples legs about metrics... It's really all about what you get used to. I grew up learning metrics, but in a practical life, we all used 2x4s, 1x6s, and a typical small boat was 14-15'. My father was a plumber and everything was inches and fractions...Then I went to work in an environment where metric and imperial go hand by hand, and still do....

[Doug Dawson]

Anyone converted most of their operations to metric? I'm really getting tired of dealing with fractions, and one millimeter equaling about 1/25" seems plenty accurate enough.

If you use story sticks, you don't even have to measure _anything_. It's all relative.

[Dave Cav]

If you use story sticks, you don't even have to measure _anything_. It's all relative.

Yeah, measurement is the enemy of precision.

[Myles Moran]

How do you guys who have converted to metric deal with things such as router bits and dado sets? I'd love to convert, but it seems that having to deal with a 12.7mm straight router bit could make the math a bit weird. It seems like so many things seem to be based on fractional inches and I haven't seen otherwise.

[Jacob Reverb]

After retirement, my father (who had been a mech. engr. and cabinetmaker who'd used English units all his life) bought a plan to build a pram using metric units.

He bought a metric tape measure, and built the boat, and when he was finished, he said he really liked using metric units, which surprised me to hear him say.

[Von Bickley]

I bought a metric tape measure to keep in my tool box for when I might need it. I haven't switched and I'm too old and set in my ways to think about switching.

[Mark e Kessler]

Makes the math easier, no more adding fractions. would need more context on the 12.7mm router question...



How do you guys who have converted to metric deal with things such as router bits and dado sets? I'd love to convert, but it seems that having to deal with a 12.7mm straight router bit could make the math a bit weird. It seems like so many things seem to be based on fractional inches and I haven't seen otherwise.

[Randall J Cox]

Know this has been cussed and discussed over the years on all woodworking forums.... With that said, I convert to metric for lots of stuff, use Siri on my iphone for this mostly. Lived in Europe with the USAF for about 8 years back in early 70s and late 80s, metric really easier to use. Also downloaded a fraction app on my phone to deal with fractions. Between the two, life is good! Randy

[Halgeir Wold]

In many cases it doesn't matter if your router bit is 12mm or 1/2", but if you're making a dado or something of the sorts, you just make sure whatever goes into that dado fits.... it really isn't more compicated. When you get used to it, you just know that your 1/2" is 12.7mm, 1/8" is 3mm+ ( 3.15), 3/4" is 18mm+ ( 18.9 - or just shy of 19mm... When you're used to it, it's just like tying your shoe laces....

[Myles Moran]

Makes the math easier, no more adding fractions. would need more context on the 12.7mm router question...

The big one that comes to mind is on a blanket chest I've built a few times, I'll run a 1/4" slot down the middle of the wood for the panels, and use a 3/4" but to take off 1/4" on each side of the mating pieces. If I had a 6mm bit and planed my wood to 18mm it'd work just as well, but instead I'd have decimal mm to add up

[Ben Rivel]

Metric is definitely a better system, but there is way too many things using imperial here in the US to try and convert. Making conversions back and forth just opens up too much room for error and mistakes. Until the US finally decides to switch over, Ill be sticking with Imperial.

[Halgeir Wold]

Well... ofiicially, there are two countries left in the world that use imperial units, - the USA and ..... Myanmar....:cool:
Sorry, guys.... I just couldn't resist......;)

[ChrisA Edwards]

I would love to go metric, but my hold back is all my measuring tools are Imperial and pretty much would become redundant.

I estimate to replace the hand tools, plus the measurement systems on my table saw, planer, etc, would cost about $600-$800 conservatively.

[Frank Pratt]

I finally went metric a few months ago and it as been a non-event. The most painful thing is that the tape I like to use the most is metric/imperial & I hate those. I'll remedy that soon though. I really don't miss the inches at all.

[Grant Wilkinson]

Don't let anyone tell you that Canada has gone metric - at least when it comes to carpentry and woodworking. Joists are still on 16" centers. We still buy plywood in 4 x 8 sheets. Framing lumber is 2 x 4s. The fact that were are somewhere in the middle causes no end of problems. 3/4" plywood is not 3/4". It is 19mm. But the sheet is 4 x 8 or maybe even 49" x 97" so that it yields a 4 x 8 with square corners. The router bit used to make the dado to accept this plywood is a 3/4" bit. So it no longer fits the plywood the way it used to. It's a real pain in the butt.

[Brian Holcombe]

I prefer decimal inches over anything else.

Plywood is weird, it’s metric, poorly converted to imperial and generally sold in 4’x8’ sheets. It’s the making of a woodworking based standup routine.

[Mike Kees]

I have quit milling my lumber to imperial dimensions,for some reason 3/4'' has always felt to thin to me. I find it far easier to mill to 20mm thickness. Also has made set up on my shaper easier for rail and stile cuts. As Grant said earlier officially we are Metric ... in real life especially as a carpenter we are stuck between two worlds. Our plywood dimension of 4'x8' will never change unless the U.S. changes,so never. My apprentices still go to technical training and work in "Metric" with "soft conversion" sizes for 2"x4" like 38x89' s. I would love to be able to frame in Metric,all the math is easily accomplished in your head. In reality I will probably be stuck with using two systems for life.

[johnny means]

If you use story sticks, you don't even have to measure _anything_. It's all relative.
Story sticks won't work in the vast majority of woodworking.

[Derek Cohen]

I initially grew up in Imperial, and school converted to Metric when I was 10 years old. My life experiences kept both alive. Over the years in woodwork, the push of hand tools made Imperial more important - all the old chisel and plane blades were in Imperial. It becomes important to slave the two areas. As machines, especially European machines, have increased their presence in my work shop, so there has been the increased need to work with Metric.

Life would be cheaper, not necessarily simpler, if there was one system. As it is, both co-exist in my workshop. This is not a big deal since I can visualise in both.

Here is an example of Imperial Wood Owl bits (on the far right) for braces, along with Metric Star-M bits for the drill press or cordless drill ...

https://i.postimg.cc/1XfFptth/Drill-bits1.jpg

https://i.postimg.cc/3NVv9T4y/Drill-bits2.jpg

Regards from Perth

Derek

[Doug Dawson]

Story sticks won't work in the vast majority of woodworking.

That is not true. It's correct that there are some places where it's useful to measure, but most of the time you're using the story stick to do it.

[Michael A. Tyree]

Ones age matters in the scheme of things. I am 76 and lived many years off metrics but once i entered into the world of skilled trades (several overall) I became sort of bi-lingual as it were. I still see no problem personally thinking in both directions, for the work at hand and as the situation dictates. In industry we worked both directions and during apprenticeship had math up through first year trig and calc so not hard to think in numbers. I still keep my old shop math book at hand from apprenticeship for those times real math comes into a design and I've forgotten the basics. it very similar overall to the math book anyone my age had around the Jr High 7th & 8th years of math class. I got into British cars long ago and Whitworth tools, but came to my senses soon enough and became a German car guy, later working on them for $. On USA helos was mostly SAE, then in industry a smattering of all the above, mostly SAE. I went back to college at age 30 in 1973 and wrote a paper in my Technical Writing class on a hot topic of that time- Metrification. I remeber certain companies who were international, yet stubborn to switch, one was Caterpillar. I wonder how many billions of $$$ it cost them to Asian mfg.'s over the years since then?
In my shop, sawmill, etc., I think fractions in wood and will never change. I change to decimals when into a machine and go metric on my motorcycles, scooter and cars, except the Ford F-150:) of course...

[Pat Barry]

Just going metric because you don't like fractions is mind boggling. You will be doing metric to inch and foot conversions and back again, at least mentally, more probably with a calculator for the rest of your life. This just makes things worse, not better. The only people who like metric are either born into it, or use it for scientific endeavours. Scientists are smart enough to separate their science from everyday life. JMO. YMMV

[Rod Sheridan]

How do you guys who have converted to metric deal with things such as router bits and dado sets? I'd love to convert, but it seems that having to deal with a 12.7mm straight router bit could make the math a bit weird. It seems like so many things seem to be based on fractional inches and I haven't seen otherwise.

Hi Myles, dado is easy, you shim to the desired width. In my experience I would never design a part that’s 12.7mm, I would use 13mm.

As you’re aware plywood in NA has been metric in thickness for decades, and of course metric router bits are available, most of the tooling in the world is metric.

I went metric in design and fabrication more than a decade ago. I find it far easier to use.

In practice nobody can tell if a leg is 2 inches thick or 50mm, so go to easy sizes. No 3/4” thick material, use 20mm, it makes the arithmetic so easy....Rod

[Rod Sheridan]

Pat, I went metric in woodworking in my late forties.

I don’t do any conversions, if I am building a shed I use Imperial as sheet goods are Imperial in width.

When I make furniture or cabinets I use metric as it is much simpler, and of course cabinets are based on the 32mm system so stay with metric.

I almost never do any measurement conversions...Rod

[Rod Sheridan]

Well... ofiicially, there are two countries left in the world that use imperial units, - the USA and ..... Myanmar....:cool:
Sorry, guys.... I just couldn't resist......;)


Ha, I made a shop layout drawing for my brother in metric.

He asked for it in Imperial so I converted the drawing and in the title block under scale I put “Imperial, just like Botswana”.

We still laugh about that...Rod

[Mark e Kessler]

Did anyone say they didn’t like fractions? Sorry but metric simplifies everything and its not that difficult to use both, I did say earlier that I had been using imperial for 30years which for the most part it is true Metric always took the back seat when it came to woodworking, only if I had to kinda thing. When I had my business I had to do both, now that I am in engineering metric.

There is nothing wrong with imperial and as Brian H said decimal inches is an excellent way to go as well, i can pretty much look at fractions and do it in my head no pencil paper or calculator needed, my main driver for change was that my planer readout is either metric or decimal to the thou and adjust in 5thou increments which put my feeble mind in a world of hell....

The key to switching is you need to switch it all, on your saws, planer etc... and instead of having that one metric tape measure around for that one time you need one imperial tape around. Could be tough for some as you need to rebuy your measuring rules etc, but honestly you don’t need that many and the others could be sold here pretty easily, especially that “red” stuff that everyone seems to like.

Mark



Just going metric because you don't like fractions is mind boggling. You will be doing metric to inch and foot conversions and back again, at least mentally, more probably with a calculator for the rest of your life. This just makes things worse, not better. The only people who like metric are either born into it, or use it for scientific endeavours. Scientists are smart enough to separate their science from everyday life. JMO. YMMV

[roger wiegand]

Just going metric because you don't like fractions is mind boggling. You will be doing metric to inch and foot conversions and back again, at least mentally, more probably with a calculator for the rest of your life. This just makes things worse, not better. The only people who like metric are either born into it, or use it for scientific endeavours. Scientists are smart enough to separate their science from everyday life. JMO. YMMV

Sorry, but that's just not true. The needs for conversion are few and far between, and to be avoided except in some extreme, unusual circumstance. Most of the world (both the English and metric sides) gets on just fine without having to ever do any conversions. It's been about six months since I took my shop fully metric, to date I have not yet had occasion to calculate a conversion. Sitting here I can't even think of an example of a case where I'd need to calculate a conversion in my furniture making and turning. Perhaps I'd need to do it if I needed to convert published plans, but I don't, as I draw my own. Yes, I have some tools that are marked in even imperial units (eg mortise chisels), but I don't actually care what the measurement is to several decimal places as I fit the tenon to the actual hole I've made in the wood, not to some abstract measurement. I think of that chisel as being ~12.5 mm, that it might actually be 0.5 inches makes no practical difference to my work. I've never measured it to know what its true dimension is-- it could easily actually be 12.7 mm and just marked 1/2".

If you assume plywood or any other pre-dimensioned material is an exact measurement of either sort you will soon be sadly disappointed-- if it matters you'd better put a tape or a caliper on it to find out what it actually is in your favorite units.

The only times I've had to do any conversions in recent times has been in cooking, where it's even more complicated as one needs to weigh stuff to make the shift from recipes given in cups and tablespoons to grams. But, there again, especially in baking, one's outcomes become more reproducible with fewer errors once you have a "metrified" recipe.

[John Gornall]

School was imperial, college science metric, engineering imperial, went to work for a Swedish company metric, moved to New Zealand, imperial, on to Austrailia metric, back to Canada both, to New Zealand which converted to metric while I was there, back to Canada where anything goes and did some work in the USA imperial. I can work in either. But my woodworking is imperial, I like fractions as I can think in 16ths or halfs or whatever suits. And I commonly use decimal inches. My neighbour recently gave me a really hard time about not being metric in my wood shop then asked me to rip a board 14 1/2 centimeters wide. He didn't get why I was lauging.

[Frank Pratt]

Just going metric because you don't like fractions is mind boggling. You will be doing metric to inch and foot conversions and back again, at least mentally, more probably with a calculator for the rest of your life. This just makes things worse, not better. The only people who like metric are either born into it, or use it for scientific endeavours. Scientists are smart enough to separate their science from everyday life. JMO. YMMV

Why on earth would I be converting back & forth all the time? I do occasionally have to do a conversion if there is some imperial measure that for some reason has to be incorporated into the project, but that is very rare. I don't understand your logic at all. Perhaps you could explain.

[Brian Holcombe]

I don’t understand the opposition to fractions. It’s handy for joinery layout. I could use decimal inches for everything but I always use fractions for layout, often I convert to decimal inches for processing the joinery but those numbers are hardwired into my mind.

[roger wiegand]

It may be an age thing. I used to be able to do it in my head, but now I find I have to stop and write it down and/or pull out a calculator when I want to know what a third of 9/32's plus 7/64ths is. Enjoy it while you've got it! :rolleyes:

[Myk Rian]

I bought a dozen inch/mm dial calipers as gifts for the kids and grandkids I think may use them. They never need batteries,
421516

[Brian Holcombe]

It may be an age thing. I used to be able to do it in my head, but now I find I have to stop and write it down and/or pull out a calculator when I want to know what a third of 9/32's plus 7/64ths is. Enjoy it while you've got it! :rolleyes:

1/3 of 9 is 3/32 which is 6/64 +7/64 = 13/64. Fractions :D

[Ted Reischl]

I use both, but I am not fond of metric. Here is one reason, wrenches:

Inch . Metric

1/4 . . . . .6mm
. . . . . . . .7mm
5/16. . . . 8mm
. . . . . .. .9mm
3/8. . . .. 10mm
7/16 . . .11mm
1/2. . . . 12mm
. . . . . . .13mm
9/16. . . .14mm
. . . . . . 15mm
5/8. . . .16mm
11/16. . 17mm
. . . . . . 18mm
3/4. . . .19mm

Notice that it takes 5 more wrenches in a standard set to cover the range from 1/4 to 3/4. Why? So we can all pay more for a wrench set? Or be hunting for the correct size longer?

And think about this, it is not just 5 wrenches. A wrench set is pretty useless if you only have one of each size unless you like rounding things off with an adjustable wrench. So you wind up buying 10 more wrenches to cover the same range. Oh, it gets worse, you also have to buy all those extra sizes in sockets, both standard and deep.

Then there is the other little matter. Scales. 10 tiny divisions between each major division? Oh, that makes it easy, sure. It is like having to always read the 1/32's on an imperial scale. Imagine what that would be like, no 1/16ths, no 1/8ths, no 1/4's, just ten itty bitty hard to see marks.

BTW, what ever happened to the "decimeter"? Never see or hear anyone use those at all. Just millimeter, centimeters and meters. Guess it was too complicated for people to remember which was which, huh?

Now don't get me wrong, there are some things I like about metric sizes. End mills are one of them.

But this whole business about "oh, it is so much easier to divide". Uh huh, at some point you wind up with decimals. I will admit that if something is designed from the ground up in metric without having to use standard off the shelf materials it is somewhat easier to work with. But if you want to mill up a 2X4 to various thicknesses you start out with 38.1 mm.

It makes more sense to work with an inch, divide it into ten units and go from there, at least you would be able to see the little lines and even put a bigger on at the .5 mark.

Division is much easier for me in imperial units. Something is 5/8 of an inch and I need half that. Simple, just double the denominator and you have half, 5/16. 1/4 of 5/8? Easy. Multiply the denominator by 4 and you have the answer, 5/32.

I spent my career working with fractions and have most of the decimal equivalents committed to memory.

But like I said above, the part I really do not like is having to purchase more tools to cover the same range as an imperial set covers. No wonder today's auto mechanics need those big honking tool boxes! If cars were still in metric they would only need about half the space, LOL.

BTW, I just looked on Amazon. Unbelievable! They charge more for an SAE wrench set with fewer tools that covers the same range as a metric set with more wrenches. Marketing people:::::::::::grrrrrrr::::::::::::

[Bob Falk]

I stick with imperial because it keeps my mind sharp doing all those conversions. :D Actually, I am too lazy to change.

[Jim Becker]

Yep, over a year ago I went metric and haven't looked back, at least for my own work. I have some client work that I necessarily need to do in Imperial because of specifications and sometimes provided artwork...this is largely subcontract stuff so I have to work in the same dimensions as the client or it gets to be a difficult conversation. I don't like mixing two measurement systems in the same project. The transition was uncomfortable for a little while, but I persisted and now I'm starting to think in metric without having to pause as much to "mentally convert" approximates for visualization. I know what 200, 400, 600, 800, etc., mm represents "in space" now, more or less. Most of my tooling (router bits for the CNC) is Imperial size, but that really doesn't matter because the software and machine deals with that transparently.

There have been a number of debates around this over time here. IMHO...it doesn't matter what an individual prefers and uses as long as they are consistent and avoid mixing systems as much as reasonably possible. Neither metric or Imperial or whatever are "inferior" to another. They are just units of measure. Use what you like and don't be afraid to try alternative, either if it's appropriate, required for a project or just to test the waters. At a minimum, I believe it's a very good idea for anyone to at least be "conversant" in the alternative measuring system simply because at some point, most, if not all of us, are going to be interacting with someone using the alternative. It's a little harder to do that for many folks growing up in North America (primarily the US) because we never learned metric in school or even if we did, there was nothing that forced us to use it. It's the standard in many industries while often "hidden" from the general public, too. Many folks in other geographies have been exposed to both metric and Imperial to a greater degree.

[Tony Latham]

Anyone converted most of their operations to metric? I'm really getting tired of dealing with fractions, and one millimeter equaling about 1/25" seems plenty accurate enough.

I'm sticking with inches. Fractions can be a pain but I've got a fraction calculator on my phone that fixes that has fixed that issue. I think it's called FractionCalculator. 5/16" + 7/8" = 1-3/16".

[Rod Sheridan]

Ted, as you’re aware, most of the tooling in the world is metric.

That can result in premium prices for oddball tools such as Whitworth or Imperial.

You’ve also left out a lot of the fractional wrench sizes which increment in 32nds of an inch, so your comparison isn’t actually factual.

I would have to spread both sets out and count them, however I have approximately the same quantity of wrenches and sockets in both my Metric and Imperial sets.

I may even have more in the several British sets it requires to have a complete array......Regards, Rod

[mreza Salav]

As somebody who grew up metric and learned inches later (and uses both) I never really understood why working with one is difficult because of having tools etc in the other. For example, why dado sets of 3/4" is important when your plywood is never 3/4" really and I always cut those things to fit. So all it matters is to pick a system and stick to it in a project all along. All my tape measures are dual metric/standard.

[Alex Zeller]

Never realized it was much of a problem for people. When you deal with fractions on a regular basis it just makes sense to most people. Metric is nice as well but the numbers start to get big quickly. 6' 2 1/2" is much simpler for me to visualize than 1892 millimeters. Or 1.892 meters. Another example is measuring a storefront opening that's 48' wide. That's 14.6304 meters. When everything related to construction in the US in inch and foot dimensions that's what you grow accustom to (even yards aren't widely used).

I look at a cut off I can quickly say to myself that's 4' long. I'm sure if grew up and spent my whole life using metric measurements it would be just the opposite. I can remember the debate back in the 70s about it. Probably had we switched by now nobody would think twice. But I can't see us ever switching in the future. I even have a set of British Withworth wrenches needed to work on a triumph motorcycle.

[Mel Fulks]

Agree with Alex! If the metric SYSTEM is so good use it ! Seen to many plans with dimensions like: 27, 572 mm.

[mreza Salav]

Never realized it was much of a problem for people. When you deal with fractions on a regular basis it just makes sense to most people. Metric is nice as well but the numbers start to get big quickly. 6' 2 1/2" is much simpler for me to visualize than 1892 millimeters. Or 1.892 meters. Another example is measuring a storefront opening that's 48' wide. That's 14.6304 meters. When everything related to construction in the US in inch and foot dimensions that's what you grow accustom to (even yards aren't widely used).



You picked your numbers because it works in your favor. The same thing can be said about inches: 1 meter is 39.3701inches. Which one is easier to remember?
This way of comparing the two system is pointless. There is a reason that the rest of the world has gone metric.

[David Zaret]

i'm going metric because much of our equipment and tooling is metric. as we've stepped up in quality of machines, with the digital scales and accuracy to measure in tenths or hundreds of mm, it has become clear that we should transition. our shaper cutters, for example, all come with specifications in metric, and we can enter those specs into our (metric) digital shaper to set the fence and spindle, and it's done - no fuss, no translation. so, i now prep my 3/4 stock to 19mm, per the DRO on the planer. tooling and tools has pushed us.

[Ted Reischl]

Ted, as you’re aware, most of the tooling in the world is metric.

That can result in premium prices for oddball tools such as Whitworth or Imperial.

You’ve also left out a lot of the fractional wrench sizes which increment in 32nds of an inch, so your comparison isn’t actually factual.

I would have to spread both sets out and count them, however I have approximately the same quantity of wrenches and sockets in both my Metric and Imperial sets.

I may even have more in the several British sets it requires to have a complete array......Regards, Rod

I will agree that Whitworth are oddball tools, but Imperial? Give me a break! If they are so "oddball" then try tossing out your Imperial tools and see how things work out for you. They might since you are in Canada, but then again, maybe not.

I did not leave out any standard wrench sizes, none. Standard hex head bolt sizes are as I listed them, try looking here: https://www.boltdepot.com/fastener-information/bolts/us-bolt-head-size.aspx and you will NOT see any wrenches in 1/32 sizes. Those were around when I was a kid about 60 years ago. Probably a hold over from when folks made things in weird sizes on automobiles.

It pays to check your facts before you tell someone else they are not being "factual". Fact is there are no standard bolts made that have a head requiring a wrench in 32nds.

But I can tell you this, I just assembled a shredder/chipper and it had bolt heads that required 13 and 14mm wrenches even though they were both 8mm bolts. One of the bolts was standard, the other had a flange type head.

I stick with what I said above, for STANDARD sets of wrenches it requires more metric wrenches to cover the same range. A quick google search reveals that to be the case.

Edit: Try doing a search on Amazon for wrenches in 32nds. . . . they are available in smaller sizes, but what I was talking about is a wrench set for the nuts and bolts sizes that are commonly encountered. Start fooling with things like instruments and gages and one can find all sorts of interesting sizes.

[Ted Reischl]

There is a reason that the rest of the world has gone metric.

And what reason would that be?

Over the years I have read several, among them:

It made numbers easier for scientists like astronomers.
Europe wanted to inflict a huge cost on changing over America's tooling to conform and make them more competitive.
Because we have ten fingers and toes.
the list may be endless. . . . what is stated as a reason is not always the real reason. something I have learned in my 70+ years on this planet.

[Mark e Kessler]

“It made numbers easier for scientists like astronomers”

Correct (for the most part) and because of their genius and practical thinking we can all now benefit from a coherent system of units for those that choose...LOL...



And what reason would that be?

Over the years I have read several, among them:

It made numbers easier for scientists like astronomers.
Europe wanted to inflict a huge cost on changing over America's tooling to conform and make them more competitive.
Because we have ten fingers and toes.
the list may be endless. . . . what is stated as a reason is not always the real reason. something I have learned in my 70+ years on this planet.

[roger wiegand]

"Europe wanted to inflict a huge cost on changing over America's tooling to conform and make them more competitive."

Invented in 1670, adopted in Europe (France) in 1790. Just how much standardized tooling was there to change over in 1790?

[Frank Pratt]

Some people are just terrified of the metric system, even though they clearly don't understand it or its advantages.

[Mark e Kessler]

Correct, pretty much none in the US anyway. Don’t quote me on this but I think it wasn’t until the late 1800’s that measurements started to become standardized and not everything and also don’t quote me on this... i also don’t think it was until WWII that standards went full steam ahead.

I will let the Googler’s out there comment and correct me...

[Rod Sheridan]

Agree with Alex! If the metric SYSTEM is so good use it ! Seen to many plans with dimensions like: 27, 572 mm.

Yeah, that's what happens when you convert 1,085 1/2 inches to metric...........Rod.

[Rod Sheridan]

Ted, I wind up using wrenches in Imperial about 1/3 of the time.

And I use smaller fractional wrenches in the 32nds range often.

There aren't a lot of 18 or 16mm head bolts any more, although I will admit that all my wrench and socket sets do have those in them.

Regards, Rod.

[Rod Sheridan]

Correct, pretty much none in the US anyway. Don’t quote me on this but I think it wasn’t until the late 1800’s that measurements started to become standardized and not everything and also don’t quote me on this... i also don’t think it was until WWII that standards went full steam ahead.

I will let the Googler’s out there comment and correct me...

The issue for science and measurement standards is that there aren't Imperial length standards.

In the US, the Bureau of Standards uses the metric system standards for length, and then certifies Imperial devices based upon the metric equivalent.

For guys who use a tape measure (like me) not having a reproducible standard isn't very important as I'm building a bird feeder, it can be much different if you're doing research or making precision objects.

I always laugh at the discussions over Imperial/metric as most of us have no idea about both systems.

If you put a piece of wood in my hand and asked me how many grams or ounces it is, I wouldn't know. Likewise in the Imperial system I know what the unit of weight is however I haven't a clue what the unit of mass is.

I know what my body mass is in Kilograms, I know what my weight is in pounds, I can easily calculate my weight in Newtons if need be, however as I said I have no idea what my mass is in the Imperial system.

I think that most of us understand very little of the measurement systems we use............Makes it kind of funny that we're so attached to them.......Rod.

[Ben Rivel]

I'm sticking with inches. Fractions can be a pain but I've got a fraction calculator on my phone that fixes that has fixed that issue. I think it's called FractionCalculator. 5/16" + 7/8" = 1-3/16".
Yep, those are nice too. I have a physical one from Calculated Industries (the Measure Master Pro LINK (https://www.calculated.com/prd100/Measure-Master-Pro-4020-Measurement-Conversion-Calculator.html)) and their iOS app version as well (LINK (https://apps.apple.com/us/developer/calculated-industries/id370406449#see-all/i-phonei-pad-apps)). Comes in handy!
They have this version now that is cheaper and still does fractions: LINK (https://www.calculated.com/prd212/Home-ProjectCalc-8510-Do-It-Yourself-Calculator.html#)

[Mel Fulks]

Rod, I'm curious about "lack of standards" . I thought the government had platinum rods available for mfgs. to check
product.

[David L Morse]

... in the Imperial system I know what the unit of weight is however I haven't a clue what the unit of mass is.

I know what my body mass is in Kilograms, I know what my weight is in pounds, I can easily calculate my weight in Newtons if need be, however as I said I have no idea what my mass is in the Imperial system...

Yes, the Imperial system is kind of funny that way. There are two different units of mass, the pound-mass (lbm) and the slug. Likewise there are two different units of force, the pound-force (lbf) and the poundal. Doing dynamic calculations in imperial means constant conversions using the acceleration due to the average value of the earth's gravity at the surface (approx. 32.174f/s/s). Keeping those straight is a major pain. It's much easier in metric.

If you're interested, a lbm is defined as a kilogram divided by 2.2. A lbf is the force exerted on 1lbm by the average earth gravity (it's weight). A slug is the mass that 1lbf accelerates 1f/s/s (foot per second-squared). A poundal is the force that accelerates 1lbm 1f/s/s.

I think. Maybe.

[Rod Sheridan]

Thanks David, I do now remember the poundal and slug however it's been more than 40 years since I last used them.............Regards, Rod.

[Myk Rian]

Holy crimaninny people. Just carry 2 crescent wrenches around.
Good ones, so you don't round off the corners.

[Thomas McCurnin]

Imperial for everything, except anything under a 1/16th of an inch, in which case I use my Starret dial indicator, which now that I think about it, is imperial, too, except in thousands.

[Jim Becker]

You should really only see the "interesting" metric measurements on things that have been converted. When you do your own work and design as metric from the start, that's really not a factor. And the same is true in reverse. So when you need to match a particular size "something", use the measurement units that make the most sense. That's why when I'm working for a client, I use their dimensioning choice if they have one. For my own work...I'm 100% metric now and outside of some CNC things with greater precision, I've not had to do anything smaller than a half-millimeter

[Jim Becker]

And...I really, really, REALLY, don't understand why some folks get so angry in a discussion like this. USE WHAT WORKS FOR YOU! There's no "wrong" with either Metric or Imperial unless you, the user, screws up. You still have to measure twice and cut once with both systems... ;)

[Alex Zeller]

You picked your numbers because it works in your favor. The same thing can be said about inches: 1 meter is 39.3701inches. Which one is easier to remember?
This way of comparing the two system is pointless. There is a reason that the rest of the world has gone metric.

You missed my point. Rarely do you work with a board exactly 1 meter or 1 foot. With the imperial system you break the number up. For example you don't say a board is 1 meter, 3 decimeters, 2 centimeters, and 5 millimeters. You just say 1.325 meters or 132.5 centimeters. With imperial it's broken up. 3 feet 2 1/16 inches. Either is fine but when you are use to breaking it up, aka imperial style, seeing the large numbers used by the metric system can be hard to get comfortable with.

There's no doubt that there's compromises with the imperial system. When laying out a bookshelf you have to accept that you need to work to the nearest 1/16 of an inch. Adding and subtracting fractions can be difficult if you are not comfortable doing so. Using what you feel is right for you is the answer. When your brain is condition to drive on the left side of the road and all your life driving on the left is all you've done the rest of the world driving on the right you have to relearn. Not impossible but clearly it's easier for some.

[John Gornall]

And then there's the old carpenter's measuring system - cut it 16 inches strong.

[mreza Salav]

Alex, I totally agree everybody is more comfortable to use the system they are used to. I am a mathematician and am very comfortable with numbers in any system. I am grown up with metric but use imperial for construction and even often for woodworking, but I don't agree any of the arguments put forward for imperial system. If one is used to it and finds it difficult to switch, by all means use it. Just don't claim numbers are easier in that system. Numbers are numbers.
The drawback of working with fractions (in imperial system) is that it is inherently based on powers of 2 (1/2, 1/4, 1/8, 1/16, etc), it is like trying to work with numbers in binary (base 2), compared to decimal base (base 10) which the metric system is mostly based on. Each of mm, cm, meter, etc are based on division in base 10. Nice thing is if you want smaller than mm you can simply write 0.02 (which is again base 10 divisions). Feet is 12 inch and then you break inch into fractions of base 2 and if it becomes too small then you work with fractions of base 10 (0.01" or 0.002"), etc.

[Brian Holcombe]

I typically do layout in fractions but cutout in decimal inches. Decimal inches, being the finer scale, are quite helpful in that regard.

I like the metric system for its logical progression (move the decimal place to change the unit) and imperial for practicality in building and layout. A lot of layout is division, so to me it makes sense to use a factional system for that.

[Joe Calhoon]

Interesting discussion, and I agree it should be a discussion and not a argument. If you want to switch to metric I think it depends on a lot of things. If you are a hobby woodworker, a one man artisan or a company with employees there will be much pro and con for each situation.

I have been working mostly metric for about 15 years now. What drove me to it was using European tooling on a NC shapers, profilers and tenoners and building Euro type windows and doors where all the rebates, overlaps clearances etc are in mm. We built cabinets and interior millwork for several years using decimal inch’s. At that time we were just starting to use machines with DROs and software to calculate cut lists. That system worked well and would probably still be doing that if we had not got into the euro windows and doors.

I think it is unfortunate the US did not convert with the rest of the world. If you want to go metric here you will have to be a little bilingual.
Dont ask me why but I still field measure in fraction inches. When I draw in line by line cad I use mm and when using software to calculate cut lists and drawings I convert my inch field measurements before imputing to the software. When I layout on a story pole I usually go fraction inch. Like I said don’t ask me why... Most software will convert drawings back and fourth from mm to inch. This is helpful as contractors, architects and homeowners will rarely be working or thinking in mm.
after 15 years I still find the large mm numbers hard to picture. Anything over 1500mm and I have to see it in inches. Most shops in Europe work in mm and the machines are set up that way. I believe carpenters there work more in cm.

[Rob Luter]

Nope. I'm a decimal inch guy. I've had all the fractional equivalents memorized for years.

[Brian Holcombe]

Going fully metric is difficult in the US, I recall when restoring the Maka, very simple things like a length of flexible conduit required me to either import from Europe or convert to imperial.

The same was true for most of the pipe fittings, I found the offerings available in British Standard were limited by comparison to imperial. If I had wanted to do so, every small part would have needed to be custom made to have BSPT fittings. Rather I used npt to metric air hose. The wrench sizes for those are metric.

I ran shop air lines in NPT then converted to metric at the ‘push to connect’ lines.

[Jim Becker]

Going fully metric is difficult in the US

I really do agree with this, although I think it's easier now than even a few years since more metric hardware is actually stocked in more places (out of necessity due to global manufacturing) and metric measuring tools are "slightly" easier to find now. Much of what I have in that regard is dual-scale which is spot on for my needs to support both.

[John Gornall]

Searching through various industries online - automobile, pharmacy, aiirplanes, science, space, guns, and many more it appears that the USA has mostly converted to metric.

My GMC truck is all metric

[Pat Barry]

Searching through various industries online - automobile, pharmacy, aiirplanes, science, space, guns, and many more it appears that the USA has mostly converted to metric.

My GMC truck is all metric

I would question this but really don't know. For example, autos and trucks. Hardware may in fact have converted to mettic (nothing worse than mixed hardware sizings IMO), but are the fabricated parts designed and made to metric?

[David L Morse]

I would question this but really don't know. For example, autos and trucks. Hardware may in fact have converted to mettic (nothing worse than mixed hardware sizings IMO), but are the fabricated parts designed and made to metric?

When I was involved with supplying components to the automotive market all of the drawings and specs were metric. That was about 25 years ago. Global manufacturing works best with a global system of units. That's the whole point of standardization. The standard is metric. AFAIK the only industry segment still clinging to Imperial is home building and related.

[Tom Dixon]

AFAIK the only industry segment still clinging to Imperial is home building and related.

And printing. But there we use a mixture of Imperial, Picas and Points. Of course all the European and Asian Presses and bindery equipment is built metric.

[Pat Barry]

I know the medical products has quite a basis in using inches and thousandths of an inch.