dang metric!

[DeformedTree]

On drain pipes, far as I know, Europe uses the same sizes at N.A.  they label them different, but dimensions are the same.

The US uses drainpipes in 32mm, 40mm, 50mm, 75mm, 110mm? (Outer diameter)

Hard to answer.  US waste piping is Schedule 40 PVC/ABS, but has also been various pipe standards too.  So the sizes align to https://en.wikipedia.org/wiki/Nominal_Pipe_Size

So the stuff in the walls will be 1.5", 2", 3", 4" schedule 40.  Per the link, this matches up to DN/ISO specs.  They are "notional" values either way.  That is, 2" is not 2" on the OD.  Some pipe and fittings will have mm values in () after the inch value. How correct this is, I'm not sure.  Best I have ever been able to work out, this is the same.  The sink drain connections is a whole other system of plumbing, thing wall stuff, I don't know what it aligns too. You just go to the store and buy a kit of bits that will get things routed in the cabinet the way it needs to go.

Supply at one time was galvanized pipe, that went away for copper which is the unique to supply CTS sizes (1/2" copper is 5/8" OD (it's the size plus an 1/8", then the different wall thicknesses take away ID, maintain the same OD.  Copper has also been used for waste, but rarely seen anymore.  Stuff changes often. On the waste side, there is a large assortment of adapters (ferncos) out there to adapt from all the various systems used over time.  Thus why on the supply side, it would have been nothing to change to metric sizes in the 70s/80s and have some adapters, no different than all the other transitions of  copper/galvanized/PVC/CPVC/ABS/iron pipe, etc that go on. Oh and get outside the house you might have clay pipe, or if you really "lucky" Orangeburg .

With the coming of HDPE pipe to the US, they clearly learned and are not making inch sizes, though some makers make soft conversion datasheets, which just adds confusion.  Right now this stuff is mainly used for GeoThermal/Radiant stuff, or town sewer/water mains.  Since a lot of Geothermal/HVAC stuff of that nature comes from Europe, I think they figured out it's just easier to use it all as is, and not modify it for the N.A. market. Those who watch "this old house" see monuments of plumbing made from this stuff the last few seasons.

On any of the "pipe" stuff one area that is probably different is US stuff will use NPT thread, I would assume in Europe even if the pipe is the same, the threads when used are probably G thread or similar.

I think when it comes to "pipe", it was fairly established pre-metric era all around the world, plus being a notional size, everyone was the same, so shift to metric, everyone just soft converted verses come up with something new. The Wiki linked also notes some stuff was to be phased out in the 30s yet is still used.

 

[JimD]

The label on U. S. schedule 40 PVC pipe is not it's actual size in inches although the inside diameter is close.  The sizes definitely do not correspond to mm sizes.  But my bigger point is the building codes.  Changing them is a huge cost, potentially, with nearly no reward.  Changing all the equipment that makes the piping is another large cost with nearly no payback.

The U. S. is probably around 5% of the world population but it is not 5% of the world economy.  It is about 20%.  But if suppliers want to ignore 20% of the market or count on people in the U. S. to buy metric, I have no issue with that.  I've already demonstrated I will buy metric if I want a product bad enough (my domino XL) but one of the reasons I have a DeWalt track saw is the use of inches for the depth scale. 

Arguments that amount to "the U. S. should do it for the good of the world"  or "it's in your long term best interest" are unlikely to go very far.  That is why we are where we are.  It is not people being mean or stupid, it is people doing what they want and looking out for their own interests. 

 

[AstroKeith]

The label on U. S. schedule 40 PVC pipe is not it's actual size in inches although the inside diameter is close.  The sizes definitely do not correspond to mm sizes.  But my bigger point is the building codes.  Changing them is a huge cost, potentially, with nearly no reward.  Changing all the equipment that makes the piping is another large cost with nearly no payback.

The U. S. is probably around 5% of the world population but it is not 5% of the world economy.  It is about 20%.  But if suppliers want to ignore 20% of the market or count on people in the U. S. to buy metric, I have no issue with that.  I've already demonstrated I will buy metric if I want a product bad enough (my domino XL) but one of the reasons I have a DeWalt track saw is the use of inches for the depth scale. 

Arguments that amount to "the U. S. should do it for the good of the world"  or "it's in your long term best interest" are unlikely to go very far.  That is why we are where we are.  It is not people being mean or stupid, it is people doing what they want and looking out for their own interests.

You dont have to change everything to go metric. In the UK we've been living with what are mostly imperial plumbing threads and pipe sizes. Solvent weld pipes made another confusion, as there are two different pipes of the same notional diameter! It also makes sense to maintain imperial where you have a large stock legacy product that needs maintaining, ie plumbing.

When I go to buy timber, the sizes are not obvious. Even before metrification a 4x2 sawn was different to a 4x2 PAR. We now sell our timber in the actual mm that it is presented as. If i buy framing timber its going to be 63x38mm, 89x38 or 94x44. No prizes for spotting that these are close to the old imperial PAR dimensions. No changes to building codes were initially needed.

So while we are living with the hang over of imperial measurements, we are thinking, working and buying in metric.

My hot tub holds 800 litres. Ask either of my kids how much the water weighs and they will instantly say 800kg, and importantly have a feeling of how much that is. They also know its 8/10's of a 'tonne'. Try that in in imperial units.

I recently bought a Porter Cable dovetail jig. Its nice and does a good job at a good price. Pretty soon its going to be thrown away. Why, because the cutters are very specific imperial sizes. I've imported one extra set from the US, but at a silly cost.

I also bought a WoodRiver no6 plane. Nice plane and the v3 now sold has metric threads. (its better for it too as the blade adjustment sensitivity is much better). So I bought their shoulder plane too last week.

My Mustang is one of the few cars that Ford is making a profit on. It was designed up front for the world market. LHD & RHD. EU6 emissions. Metric.

The US is going to have to migrate eventually. I suggest for the sake of your children and theirs, get on with it!
(ps: the US is about 13% of the world economy and falling steadily).

 

[DeformedTree]

Correct, the plumbing is a Trade Size, so units doesn't matter, but also in the case of it as I mentioned, it's fine to hold the old dimensions, just update the labeling. Would save the manufacture to just mark it with the global standards/sizes, no longer have 2 same but different product lines.  Other things need hard conversions, both to make sense, and match up with global standards.  The US codes and such are metric (dual measurement), they were setup expecting the change over.  Things did change, brick and concrete block changed over, but some industries pushed back. So now you can buy both inch and metric block, but metric ones may need to be special ordered in depending on where you live.  Shingles switched over to metric a while back, unless you are a roofer, you probably wouldn't even notice. Of course even though they are now metric 1m x 1/3m, they label them in inches (39-3/8).

On your car, the US auto industry switched over starting in the 70s.  They are global businesses and face global realities. All US cars have been all metric since the late 80s with random exceptions of some legacy carry over parts that never got updated, some things got soft conversion updates (labeling), other times they just went and re-did all the threaded features to metric and ran with it.  Same goes for other industries like construction/agriculture equipment.  Basically if you are a US manufacture and you sell stuff beyond the US borders everything you do is metric.  There will be exceptions and legacy bits, but for the most part you are metric unless there is some over running reason (legacy hardware install base installed globally, like some examples that others and I have mentioned).  You simply aren't going to be successful selling stuff in metric countries if it's in inches. The companies know that and converted long ago. Plus their supply chains.  Cost is king, and the reality is things like inch bolts/screws cost more when you are buying quality hardware and pulling from global supply chain. There just isn't the market for the inch hardware.  You might find a US supplier for inch hardware to supply a plant in Kentucky, but that isn't going to work for your auto plant in Germany so well. There is just no reason for using inch in this stuff. Plus the flip side, Benz, BMW, VW, Toyota make a large portion of their cars in the US, they aren't going to re-work them to inches. They need US based supply chains to support them.

This also gets to "I'm comfortable with inch" issue.  People have now grown up with the stuff around them metric, 2 generations worth of people.  From farmers to mechanics, everything they wrench on is metric, it's what they know. Just about anything you ever assemble, it takes metric wrenches.  Only reason a lot of folks have many inch hand tools around is the tool kit they bought was half and half.  But for a lot of folks, they primarily have metric tools.  Tear anything apart to fix it, again, all metric.

You can find new stuff that is in inches, but it's generally US only stuff, small companies, legacy products.

Raw material is often inches, but getting metric sized stuff for things like metal is now common. You will get folks who claim they have to do it in inches because the material is in inches and you can't get metric, they just don't want to look or accept the supply chains now do both, again, global realities.  Metal products come from mills around the world.  Same happens to wood products, lot of stuff from Canada, but also all corners of the world.

Short term, I'd just like to see stuff that is metric, not labeled with approximate inch labeling (plywood being a great example). On something like Pipe, just use the ISO labeling.  Stuff that takes real conversion, that will take longer.

 

[FestitaMakool]

What [member=72891]AstroKeith[/member] said, mostly. UK has been converting more and more to metric later than most other European country’s (Correct me if wrong).
I think from my side of view that both systems has its values. But for what we do here, dimensioning wood, it’s metric all the way. It’s just easier. To master imperial you need it in your spine. I do like the common understanding of imperial way of describing, that works across country’s. But, as also AstroKeith says, when actually measured, you see the different dimensions that is adopted for each country. We have slight different 2x’s, 1 1/2x’s and so on.

But even in my metric country, there’s loads of old imperial.
Ie: We say that a boat/vessel is 18ft, 23ft, 30ft and so on. When a boat is measured exactly, it is in meters and centimetres. We don’t say that that is a 5,49 metres boat, its 18ft boat.
Lumber: Same as you, although it’s slowly changing to metric.
Plumbing: Imperial
Wheels: Imperial (inches) - Funny: diameters in Imperial, with and sidewall height in metric..
Speakers: Mostly imperial, but both used.
Screens: Imperial
Motors: Combustion motors, HP, imperial. (They have tried adopt Kw, but no real luck yet  [big grin]
Electrical motors: Metric (Watts)
The list could be long, I’m sure other Europeans will fill in.
Though, I’ve heard of none that work in woodworking that actually work in imperial.
A woodworker and artist I met recently had lived in New York for many years, living from woodworking and art did adopt some imperial to meet standards when absolutely required, but stayed in metric otherwise. A tool (except for calipers, tapes and so on) made for woodworking is solely in metric scale. We just never see them here in imperial if not coming from the US.

 

[DeformedTree]

And that is how it will be anyplace.  What was built is built, no one is going to go changing it.

I'm a pro metric as you find in this country, doesn't mean I don't say things in Inch values, and even if we converted, there will be stuff we will speak in inch system afterwards.

Your examples are the same fairly universal.  Metric tires was this odd "failure".  I don't think anyone likes how they are dimensioned.  But yes, Inch Wheel diameter, with metric tread width, and ratio sidewall height is the norm.

A lot of examples are the part that those who resist just don't seam to understand.  If it's a 16ft boat, it will always be a 16ft boat. No one is going to come and demand it be called a 4.877m boat.  If someone relabeled it as such, I would mock them, and call it a 16ft boat, because that is what it is.  But if someone was designing a new boat, it would make sense to design it 5m long.

The issue many take is they do soft conversion, not hard conversion.  No one wants soft conversion, though in some places it makes sense.  They will say something like how they just want to say 36" or 1 yard for the width of something, not .XXXm, etc. They miss that you won't make things 36*25.4 mm,  you will just make it 1m instead.  There was an example of 36" counter height above, well, you don't make them 914.4mm,  you just make them 900mm.  But this is also why we need to convert. Since it's not just about the number, the dimensions of products/items change so things match up and work well.  IKEA has to work this hell in reverse.  They have a kitchen system, but have to modify it to be a different N.A. version to match with the 3" pitch of N.A. cabinets.  Which also means they don't bring all the stuff they have for it to the US.  So now you have US widths to things, but the rest of it is all metric, panel thickness, hardware, etc, it's all metric, except in 1 of 3 dimensions.  Metric can be hard/pointless if you don't do hard conversions and match up to the world. 

But this keeps going back to when metric stuff gets labeled in inches. It just produces madness, but also means you often have no idea what it really is. If something is 1", don't tell me it's 25mm.  If it's 1ft, don't say 300mm.  At the same time, if it is 300mm,  don't tell me it's 11-13/16" .  But as mentioned with roof singles, that exactly what they do.

Framing lumber will always be a mess. a 2x4 is 1.5x3.5 (few decades back was 1.625x3.5), but generally they aren't even that, they tend to be plus or minus and 1/8th in either direction.  So it pretty much is what ever you want to call it.  I suspect a lot of them are being made to 35x90mm based on what I keep measuring.

 

[Coen]

Your examples are the same fairly universal.  Metric tires was this odd "failure".  I don't think anyone likes how they are dimensioned.  But yes, Inch Wheel diameter, with metric tread width, and ratio sidewall height is the norm.

Huh? I buy bicycle tires purely on their metric size according to ETRTO standards. Buying based on inches is way more likely to get you a tire that doesn't fit. My Brompton has 16" tires... good luck with that, as '16"' is used for both 305 and 349 (and 18" for 355). Normal sized bicycles (28"); same story; there is the common 622, but also 635 (with 27" being 630). Just one giant mess if you don't follow the ETRTO sizes.

A few weeks ago I bought some tires; I went to the store, told them I wanted Schwalbe Marathon 40-622 and that is exactly what I got; zero confusion. If I were to say I wanted 28"x1.5 he might have asked me if I wanted 622 or 635.

Or as Wikipedia says it;
"The great advantage of ETRTO sizing is that it is unambiguous; previously, nominal dimensions were used which were interpreted in different ways by different countries and manufacturers - a problem for the end user. "

Agreed on the framing lumber; what a mess that is..

What [member=72891]AstroKeith[/member] said, mostly. UK has been converting more and more to metric later than most other European country’s (Correct me if wrong).
I think from my side of view that both systems has its values. But for what we do here, dimensioning wood, it’s metric all the way. It’s just easier. To master imperial you need it in your spine. I do like the common understanding of imperial way of describing, that works across country’s. But, as also AstroKeith says, when actually measured, you see the different dimensions that is adopted for each country. We have slight different 2x’s, 1 1/2x’s and so on.

But even in my metric country, there’s loads of old imperial.
Ie: We say that a boat/vessel is 18ft, 23ft, 30ft and so on. When a boat is measured exactly, it is in meters and centimetres. We don’t say that that is a 5,49 metres boat, its 18ft boat.
Lumber: Same as you, although it’s slowly changing to metric.
Plumbing: Imperial
Wheels: Imperial (inches) - Funny: diameters in Imperial, with and sidewall height in metric..
Speakers: Mostly imperial, but both used.
Screens: Imperial
Motors: Combustion motors, HP, imperial. (They have tried adopt Kw, but no real luck yet  [big grin]
Electrical motors: Metric (Watts)
The list could be long, I’m sure other Europeans will fill in.
Though, I’ve heard of none that work in woodworking that actually work in imperial.
A woodworker and artist I met recently had lived in New York for many years, living from woodworking and art did adopt some imperial to meet standards when absolutely required, but stayed in metric otherwise. A tool (except for calipers, tapes and so on) made for woodworking is solely in metric scale. We just never see them here in imperial if not coming from the US.

Combustion motors is in kW here. Plumbing also metric.

To add to your list; pressure. Usually [bar] instead of [Pa], sadly.

 

[semenza]

I think he is talking about car tires which are,  for example,    65/225 R16  The R16 being 16" wheel diameter with 65/225 metric height to tread width ratio. The width is 225mm and the height is 65% of the width.

Seth

 

[FestitaMakool]

That’s correct, Seth.

Albeit not interested in bicycles other than taking a spin very now and then for fun. I still have plenty experiences with all conflicting dimensions regarding tires and wheels [eek]

It just keeps me reminded what a plumber once answered when I asked him: “Isn’t 1/4”, 1/2” and 3/4” standard?” He answered: lThe standard is that there isn’t any standard, it’s a mess”  [big grin]

And, yeah, tire pressure is “standard” in “bar”.
I live happily with both systems, and the fact that I can measure the framing timber in my outhouse in imperial is fun. Because it is 100 years, and back then and till not too long ago a 4x4” was actually 4x4” here. But later a standard used mandatory now is TEK, when building houses. It results in som strange dimensions in mm. Just to make it harder.

 

[DeformedTree]

yeah, was speaking of car tires.  Had to look up  ETRTO,  looks to be somewhat defunct and or taken over by ISO.  Looked at their history, you can see all the struggles of tires sizing, looks like all their standards were scrapped by the mid 2000s.  Some cars were sold in the US in the 80s with "metric tires", which I think is what ETRTO specs did. They flopped. Probably because wheel sizes were so stable then, verses now where they increase an inch every couple years.  So metric tires just meant it would be hard/expensive to get replacements. Cars can be around for 100s of years, so you have a massive amount of inch rims, so changing that becomes a mess.

I know bike tires get weird, I'm not much a biker, but I know you can get confused very fast. In the past few years tires went from all being 26" to being 29" and 27.5" along with 26", I think in the US, people will jump between metric and inch designations. I just take a dead tire to the bike shop and let them deal with it.

 

[Coen]

yeah, was speaking of car tires.  Had to look up  ETRTO,  looks to be somewhat defunct and or taken over by ISO.  Looked at their history, you can see all the struggles of tires sizing, looks like all their standards were scrapped by the mid 2000s.  Some cars were sold in the US in the 80s with "metric tires", which I think is what ETRTO specs did. They flopped. Probably because wheel sizes were so stable then, verses now where they increase an inch every couple years.  So metric tires just meant it would be hard/expensive to get replacements. Cars can be around for 100s of years, so you have a massive amount of inch rims, so changing that becomes a mess.

I know bike tires get weird, I'm not much a biker, but I know you can get confused very fast. In the past few years tires went from all being 26" to being 29" and 27.5" along with 26", I think in the US, people will jump between metric and inch designations. I just take a dead tire to the bike shop and let them deal with it.

29" is just another bullshit name... it's the same 622 size as regular "  28" " bicycles have. It just tends to refer to mountainbikes // fatter tires. Eg 47-622, 57-622, 60-622 etc. while 37-622 is a more regular size although citybikes with 50mm fat tires are becoming more common too.

I've never taken dead tires to the bike shop. Why on earth would you do that except if you are confused by nonsense tire-sizing?  [wink]

ETRTO isn't taken over by ISO... they literally created the current ISO 5775 norm.

 

[AlexThePalex]

If you think converting to metric is the challenge ....... just wait till the Asian countries have to get rid of their old fashioned and overly complicated characters and start using the Latin alphabet. Same for Russia and cyrillic.

 

[WillAdams]

China, Japan and Korea using Latin characters is easily handled using the same systems implemented for Morse code.

For Korean for example it's SKATS, Standard Korean Alphabetic Transliteration System.

 

[JimD]

All or nearly all the materials I use for woodworking in the U. S. are sized Imperial.  Hardwood is in board feet.  Sheet goods are 4x8 foot sheets (although thickness may be in mm).  Fasteners are numbers for screws (#4, #6, #8, #12 etc), inches for bolts.  Drawer slides are sold in inches.  Bits to make the holes for screws are sized to the screw number.  Router bits have either 1/4 or 1/2 inch shanks and roundovers are in fractional inches.  It is possible to find metric bolts but I don't know about metric screws.  It would be a bit challenging to buy raw materials and some tools to metric measures.  But I use imperial due to preference, not difficulty. 

It isn't woodworking but I moved a couple gates last week.  Fasteners were in inches and I needed my inch size sockets and wrenches.  But later in the week I tried to fix a couple things on my BMW and needed my metric tools.  Would have also been metric fasteners if I messed with my Ram pickup. 

Cars are one of the few things that are more metric.  But the weight is still given in pounds (but the KgU will be in the owners manual), tire pressure is in psi, the motor spec is in hp and lb ft of torque. 

I used to have a job where my primary responsibility was to sell nuclear fuel assemblies.  I had a boss who like to ask you when a negotiation would close.  Next he would ask why.  His point was that if your date was based upon the customer promising senior management or a regulator he tended to believe it.  If it was just your estimate, the safe assumption was that you were being optimistic.  The application to this situation is the lack of a forcing function, I believe, for the U. S. to convert everything to metric.  The question is why.  To me all the answers I've heard sound weak.  That suggests the conversion will not happen at all, or at least any time soon. 

 

[Coen]

4x8 in funny units is just what we call 2,44 x 1,22 here.

It starts with not teaching your children units that are supposed to disappear in school. People coming out of the school in NL now often usually don't even know the funny units anymore.

And when grandma asks the 18 yr old in the food market for "2 ons" (1 ons being 100 gram) of beef, she is gonna get the question; 'two what?'.

When I asked my 19 year old niece what one inch was, she said "about 1 cm". Then she went to live in the UK for a while and her mother (my sister in law) said she lived close to the train station; "only like 2 km" but in fact it was 2 mile, being 3+ km.  [tongue]

That change is possible can be seen with Torx; once we had slot screwheads, phillips, pozidrive, but now there is Torx and it's widely used, simply because it is better.

 

[junk731]

4x8 in funny units is just what we call 2,44 x 1,22 here.

Its funny what people call funny units.

It starts with not teaching your children units that are supposed to disappear in school. People coming out of the school in NL now often usually don't even know the funny units anymore.

They tried that here too. It was sort working until they started looking for jobs in house, landscape etc construction or plumbing and had to be reeducated to the existing system of measure which was imperial. This happens at the college level when apprentices are sent for mandatory training. If you went anywhere here and asked for 2.44 x 1.44 they would look at you like you had a third eye.


I'm sure one day you might see a total change but I wouldn't hold my breath.

 

[Jim_in_PA]

4x8 sheets of plywood, etc, vary greatly in the US. The "good stuff" I get from Industrial Plywood is typically 1245x1225mm (~96.5"x~48.5")

But again, it doesn't matter one one personally chooses to use. But I for one would prefer that we would achieve on system globally and given adoption already in place, that would be metric.

 

[Coen]

4x8 in funny units is just what we call 2,44 x 1,22 here.

Its funny what people call funny units.

It starts with not teaching your children units that are supposed to disappear in school. People coming out of the school in NL now often usually don't even know the funny units anymore.

They tried that here too. It was sort working until they started looking for jobs in house, landscape etc construction or plumbing and had to be reeducated to the existing system of measure which was imperial. This happens at the college level when apprentices are sent for mandatory training. If you went anywhere here and asked for 2.44 x 1.44 they would look at you like you had a third eye.


I'm sure one day you might see a total change but I wouldn't hold my breath.

4x8 sheets of plywood, etc, vary greatly in the US. The "good stuff" I get from Industrial Plywood is typically 1245x1225mm (~96.5"x~48.5")

But again, it doesn't matter one one personally chooses to use. But I for one would prefer that we would achieve on system globally and given adoption already in place, that would be metric.

It's funny you both have some errors in there, just giving more reasons why it should be all metric  [cool]

 

[Jim_in_PA]

Coen, the mm measurements I stated (which I actually use for my work) are accurate. The other numbers have the tilde in front to note they are approximate. I switched to metric two years ago for all projects that would allow it. Some work I do for other makers I have to use their preferred system, however.

 

[wmarazita]

Coen, the mm measurements I stated (which I actually use for my work) are accurate. The other numbers have the tilde in front to note they are approximate. I switched to metric two years ago for all projects that would allow it. Some work I do for other makers I have to use their preferred system, however.

You might want to check that again......a little more carefully.