LOL, US imperial weight standards are base on the Metric System Kilogram! - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: May 10, 2017, 05:46:14 pm
content: I cant believe it myself.

author: b_force
author_rank: Super Contributor
timestamp: May 10, 2017, 05:51:02 pm
content: You just beat sharing this video.I thought it was pretty funny.The circle is round after all

author: Len
author_rank: Frequent Contributor
timestamp: May 10, 2017, 05:52:10 pm
content: The inch is also based on the SI standard.

author: b_force
author_rank: Super Contributor
timestamp: May 10, 2017, 06:02:08 pm
content: btw, since it's a derived unit, that also means by definition it's less accurate.

author: SeanB
author_rank: Super Contributor
timestamp: May 10, 2017, 06:23:38 pm
content: They are quite small in real life, but still, that you have a million dollar block of material, that is known to nearly the picogram how much it weighs compared to all the others. seen one locally as well, it was visiting to be used as master verification.

author: georges80
author_rank: Frequent Contributor
timestamp: May 10, 2017, 07:41:18 pm
content: Some extra madness....https://www.driveclean.ca.gov/Know_the_Rating/Understand_the_Smog_Rating.phpCheck the measurement unit... g/mile... wtf?cheers,george.

author: Ampera
author_rank: Super Contributor
timestamp: May 10, 2017, 07:57:55 pm
content: As an American, the term US Imperial system annoys me, as our system is technically not the Imperial system, but rather is derived from it. It's actually called US Customary measurements.The other fact of the matter is that the US is sort of like the UK when it comes to our use of the Imperial/US Customary systems. In the UK roads are measured in miles, I'd wager to bet they still use Imperial units to measure lumber, bake cakes, and maybe even in some places measure gas.If your anybody in the US, you use Metric/SI. No major corporation that does not have to directly sell to the American public (And even still then) uses Metric. All of our ports are in metric, all of our trading is in metric. You can buy metric screws, tools, and even measuring cups here. Unless your building a house, baking a cake, or using a road, then you probably aren't using the US Customary system.And yeah, we all know that today the Imperial/US Customary measures are defined by Metric. I don't see why this is all that amusing. Very few people in the US would say with a straight face that our customary measures are better than the Metric system. The only reason we don't change is that we are a country of ~350 million people with a lot of land to give to them, and changing every single inch and ounce within it would not be worth anybody's time.I doubt we will stay with our US Customary measures for long. It's been taught in schools for years, maybe even decades now. Every reasonable and educated person can use metric units. The customary units are more of a consumer unit for small tasks that don't have a lot of maths involved.Don't ridicule the US for not changing to metric, unless your one of the four countries in the exception, we have more land and people than you do, so changing everything outright is more trouble than our already broken, mismanaged government is willing to go through.

author: Gyro
author_rank: Super Contributor
timestamp: May 10, 2017, 08:00:07 pm
content: It seems to me that any comparison of units with a non-interger relationship is going to bite you in the ass sooner or later. It's just a matter of time and technological evolution.

author: yada
author_rank: Frequent Contributor
timestamp: May 10, 2017, 08:03:33 pm
content: Quote from: SeanB on May 10, 2017, 06:23:38 pmIn the video he said that they would be off by 100mg just from air displacement of different volumes. That's huge when setting the price of a piece of iridium or platinum. I don't think the masses of the weights changed but rather some other condition is causing those huge variations. No way that much O2 would react with nonreactive metals, or the metal would sublimate or wear off. No way of really knowing until we start comparing to the silicon sphere.QuoteI thought the official standard was football fields? Everything seems to be compared to the length of football fields when you watch American TV. But speaking of land what does it have to do with converting to metric? We have more land mass then the US and we have metric.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 10, 2017, 08:07:08 pm
content: The imperial system is slowly dying away in the UK as the old codgers end up 6feeterr 2m under. The roads are in miles out of convenience more than anything - converting 35 million road users to obey 110kph is not an easy task, whereas going from cups of sugar or ounces to grams just relies on generation leaps.Besides, these measurements are arbitrary to most people and are just numbers and people end up thinking like Dave when he was doing his PCBs. Sometimes using Imp is easier than SI and vice versa, especially where base 12 makes the math easier.

author: mmagin
author_rank: Frequent Contributor
timestamp: May 10, 2017, 08:16:14 pm
content: Quote from: TwoOfFive on May 10, 2017, 07:57:55 pmMe too. I'd have to keep a lot less fasteners and tools on hand if it weren't for this bullshit.What's amusing is that the Chinese manufacturers of the cheap consumer goods that end up in places like Home Depot have been perfectly happy to indulge the US predilection for Imperial units. I almost wonder if Imperial units would have died out faster otherwise.

author: Ampera
author_rank: Super Contributor
timestamp: May 10, 2017, 08:24:41 pm
content: The reason I say land has anything to do with it is because of roads. If we convert to metric 100% to the state of a country like Germany or France, then we would have to renumber, resign, and remark all of our roads, and for a country that is just behind Canada, but with literally 10x the people, that would mean a LOT of roads, and a LOT of money. With what RGB said, we could foreseeably change everything else but the roads, but that doesn't leave much. Our lumber and tools are Imperial and that would be a COMPLETE nightmare to change. All lumber mills would have to mod their machines to mill wood to a metric size, and contractors that are already used to the regular sizes would have to change over.Screws are the same thing. This is actually sorta funny. For those who have built a computer, you have used Imperial measured screws. I forget which, but either the coarse or fine thread screws are Imperial.After that it's really just gas and baking. Gas doesn't really need metric, and baking is just fine with Imperial.And I hate football too. Not the kind where you actually USE your foot, that's fine, but the kind where a concussion is just as common as a touchdown.

author: The Soulman
author_rank: Super Contributor
timestamp: May 10, 2017, 08:26:54 pm
content: At 5.00 min in the video he must be wrong stating different displacement volumes in air can cause up to 110mg of difference,perhaps in water but not in air, somebody got their notes mixed up..

author: TimFox
author_rank: Super Contributor
timestamp: May 10, 2017, 11:18:44 pm
content: Please note that the kilogram is a measure ofmass, but in careful usage the pound is a measure ofweight.The difference is covered in high-school physics classes.

author: b_force
author_rank: Super Contributor
timestamp: May 10, 2017, 11:22:18 pm
content: Quote from: TwoOfFive on May 10, 2017, 08:24:41 pmEven that is no real men sport.Ask Dave (and all other Aussies) THEY know what rugby is.No protection, no nothing, just wrap your head in some tape if it's starts bleeding.Btw, football (soccer) is more like an excuse to demolish whole cities nowadays unfortunately.I get the practical point about the imperial system.In fact, if I had no ruler, just on a lonely island with my bare hand, the idea with fractions (like how it works with inches) makes a lot of sense.I think the whole debate is so heated up because some people brag about it a bit to much.Which is especially annoying if you know that it's not even the world standard.

author: b_force
author_rank: Super Contributor
timestamp: May 10, 2017, 11:28:43 pm
content: Quote from: TimFox on May 10, 2017, 11:18:44 pmEhm what I learned in high-school physics is that mass is a property of a certain object (or body said properly)Weight may only be used if you involve the gravitational force.The first thing my physics teacher did with ALL other units, wrote them on a piece of paper, grabbed the bin and trashed it!Rubbish!! He yelled. We only have kilograms, meters and newtons, newtons are derived from all other SI units, which are...... (class had to answer)If you would use the word pound or whatever in your answer, there would be a big red mark

author: sibeen
author_rank: Frequent Contributor
timestamp: May 11, 2017, 12:23:31 am
content: I love the mix and match approach. For instance Arc flash incident energy levels are generally measured in terms of calories per square centimeter (cal/cm2). Now you know that whoever wrote the original paper on this had to be from the USA.

author: karoru
author_rank: Regular Contributor
timestamp: May 11, 2017, 12:47:05 am
content: Quote from: sibeen on May 11, 2017, 12:23:31 amNah, whoever wrote the original paper was only old enough. Calories were commonly used in CGS (centimeter-gram-second) era - you used ergs for mechanical work-related energy and cals for heat-related energy. Only after MKS (meter-kilogram-second) became a thing people agreed to use the same unit for both.In every single European/American physical chemistry/thermodynamics textbook before say 80's you'll find "mechanical equivalent of heat" with constant for converting between cals and ergs;)

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 11, 2017, 01:17:44 am
content: For engineers and scientists the metric system has great advantages. For the vast majority of people it really doesn't matter. Miles and kilometers are just a number describing how far it is to grandmas house and both work fine. Cooking and baking actually are a mixed bag. Metric avoids a whole slew of troublesome conversions, but the myriad of customary units melds well with the art vs science nature of cooking. A dash of salt is deliberately vague and derives no benefit from being defined as 100 mg or whatever. The construction trades really wouldn't glitch much. It is my understanding that dimensional lumber and plywood is much like electronics layout. Some electronic parts use 0.100 spacing, others use 2.54 mm and both fit on the same PWB. There are also parts whose primary spacing is metric. Same thing exists for lumber.Those who really benefit from metric should also be conversant enough with both systems that it doesn't really matter. I worked on a military system once that had the strangest conglomeration of units. Performance in terms of range was measured in kilometers, speed in Mach numbers. The size of the system was in customary units as was the weight, but operating temperature range was metric. The system included a camera component. Aperture diameter was inches, while aperture area and focal length were metric. Detector elements had sides measured in inches, but areas in sq cm. This mishmosh was everywhere, but it worked. The famous Mars lander error occurred not because of mixed units, but because of an assumption that units were not mixed. A similar error could be made entirely within the metric system if anyone anywhere used decadal multipliers such as micro or kilo while someone else assumed that numbers were purely MKS (or god forbid cgs).For me the worst part of having mixed measurement systems is having to maintain tools to work two different standards. The differences are not fundamentally tied to the measurement system. There is a large element of protectionism in the original definition of metric screws and bolts as different than other pre-existing standards. Just as there is an element of protectionism in maintaining the ASME standards as the world has switched to metric. At least I don't work on older British gear and have to maintain a Whitworth set of tools also.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 11, 2017, 01:25:56 am
content: Quote from: Gyro on May 10, 2017, 08:00:07 pmQuote from: b_force on May 10, 2017, 06:02:08 pmThose statements appear to be without support. They would apply to the rest of the metric derived units as well.Besides it is proposed that the new standard for kG be a Watt-scale using Planck's Constant. Hardly integer by any stretch.And basing the US system on the metric standards probably happened before the OP was even born. Hardly seems like wild news.Besides, the whole thing sounds like a couple of 3rd grade kids on the playground saying "my dad can beat up your dad". I thought EEVblog was better than that.

author: tronde
author_rank: Frequent Contributor
timestamp: May 11, 2017, 01:27:33 am
content: Quote from: TwoOfFive on May 10, 2017, 08:24:41 pmNorway is metric. Our standard dimensions for lumber are among others:36mm, 48mm, 98mm, 148mm and 198mm. Guess why? It has someting to do with previous use of inches and how much dry wood shrink.

author: rs20
author_rank: Super Contributor
timestamp: May 11, 2017, 01:30:52 am
content: I'm a metric fanboy, but I have to say there's absolutely nothing facepalm-y about basing the US system off the metric system. What are you proposing they should do? Come up with their own, fundamentally different definition, thus making all conversions between the two actually subject to experimental uncertainties?I mean, one inch equals 25.4000000000000 millimeters,precisely. That's agoodthing. The reason that statement doesn't read as "one inch equals 25.4003(25) as of 2017 measurements" isbecausethose keeping the US system up to date chose, correctly, to be maximally harmonious with the metric system, rather than being snooty and arrogant and developing their own primary standards.If you're going to criticize non-metric measurement systems, actually make cogent arguments

author: P90
author_rank: Frequent Contributor
timestamp: May 11, 2017, 02:16:12 am
content: Quote from: TwoOfFive on May 10, 2017, 07:57:55 pm"YOU'RE"

author: Ampera
author_rank: Super Contributor
timestamp: May 11, 2017, 03:17:13 am
content: Quote from: P90 on May 11, 2017, 02:16:12 amIf I gave a damn about grammatical perfection I wouldn't have made that error. However it was a small rant, and I didn't feel the need to proofread that hard into it.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 11, 2017, 03:21:25 am
content: Quote from: BrianHG on May 10, 2017, 05:46:14 pmThis is news? It's been definition since 1893...https://en.wikipedia.org/wiki/Mendenhall_OrderFrankly I'm surprised, and a bit embarrassed, Derek didn't already know!Tim

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 11, 2017, 03:22:44 am
content: Quote from: b_force on May 10, 2017, 06:02:08 pm1 inch == 25.4mm, by definition.Threading lathes with 100/127 conversion gears can cut either thread,exactly.Tim

author: theatrus
author_rank: Frequent Contributor
timestamp: May 11, 2017, 03:23:11 am
content: The US even tried to metricfy - there are a number of road signs (probably replaced by Caltrans now) listing distances in miles and kilometers. It... didn't go well.

author: tautech
author_rank: Super Contributor
timestamp: May 11, 2017, 03:51:32 am
content: We changed back in the 70's just as I was starting work.The old guys didn't like mm's, reckoned they were too hard to see compared to 1/16 ths.Most soon got glasses.Most of the conversions become second nature pretty quick but the one I always had trouble with is the US gallon.Where on earth did that originate from and what's it related to ?Weight ? Volume ?

author: yada
author_rank: Frequent Contributor
timestamp: May 11, 2017, 04:17:35 am
content: Quote from: The Soulman on May 10, 2017, 08:26:54 pmYeah that souded way too high. We an figure out airs weight/mass usingPressure X Vol =nUMBER of mols X R(0.08206) Temp in K.One kilo of PtIr was 21.5 g/cc / 1000g = vol of little weight thing.So we take our volume of air at STP X vol of air in mg ad we subtract that from the mass of the weight? Mayb 100mg is right. Air is kind of heavy (I'm assuming air is just 80% N2 and 20% O2.)

author: moz
author_rank: Regular Contributor
timestamp: May 11, 2017, 05:13:23 am
content: Quote from: The Soulman on May 10, 2017, 08:26:54 pmAir weighs about 1kg per cubic metre at sea level (1 gram per litre), and 1kg @ density of about 20 means the kilogramme has a volume of about 50ml. That much air weighs about 50mg. The stainless steel kilogramme has a density about 1/3rd of the platinum-iridium one, so three times the volume. The extra 2x the volume weighs.... about 100mg. I could find links, but those numbers are either from the video or you should remember them (density of one... come on, how hard is that to remember)I think his numbers are right. As you'd hope from a senior NIST representative.

author: moz
author_rank: Regular Contributor
timestamp: May 11, 2017, 05:32:50 am
content: The best thing about imperial units, sorry, "US convent eunuchs" is that there are so many to choose from. We could look at the displacement question this way: Air pressure is about 15 pounds per square inch. The atmosphere is approximately 480 chains deep but the density drops to nothing at the top so we can say the density at the bottom is probably more like 218 slugs per acre. The specific gravity of platinum-iridium is about 179 pounds per gallon (US gallons) or ... you know, I give up. All those conversions are doing my head in.But I do love that you measure water in acre-feet, fluid ounces, gallons, pints, cubic yards or quarts. So many choices, none easily relatable to any other. All based on stuff that's readily to hand before the industrial age. So we get really fun units like fluid scruples (which sounds like it should measure corruption but doesn't).

author: Dr. Frank
author_rank: Super Contributor
timestamp: May 11, 2017, 08:59:47 am
content: Quote from: Len on May 10, 2017, 05:52:10 pmQuote from: b_force on May 10, 2017, 06:02:08 pmLatter is an incorrect statement, but a very interesting one, because this leads to some deep thoughts about ratio determination for any of the SI-units.At first, 'derived units' are all these, which are derived by powers, products or quotients of the 7 base units.Examples (relevant for EEVBLOG) are the Ohm (kg·m^2·s^-3·A^-2) and the Volt (kg·m^2·s^-3·A^-1).The inch is a non-SI unit of length, but it's not a derived unit. Though the inch is not recommended for use, it has the same acceptance, as other non-SI units, but which are still in daily use, like: minute, hour, tonne, litre, etc.Anyhow, NIST defines conversion factors between the SI definitions and many of the U.S. units.These factors may be exact or an approximation.https://www.nist.gov/physical-measurement-laboratory/nist-guide-si-appendix-b8The inch / meter conversion factor is exactly 2.54E-2.Therefore, thedefinitionof the inch is exact, like the meter.But there's always therealization(mise en pratique) of units.The meter is realized via the exact definitions (i.e. zero uncertainty) of the speed of light, and of the second, therefore, any fraction or multiple of the meter can be realized with zero uncertainty - within the experiment precision limits, of course.So the inch is in terms of definition AND realization as accurate as the meter itself.The length and the time are defined by invariable constants of nature, therefore universally constant and exact.Volt and Ohm are currently not exact units, neither in definition, nor in realization (~ 1e-7 uncertainty).This will also change by SI-2018. Their new definition and realization will turn them into exact units, which are also invariable and universal. The new SI - Volt definition by a Josephson Junction Array also has the big advantage, that any fractions and multiples of a Volt can be realized with zero uncertainty (within experiments accuracy), whereas the Klitzing-Ohm has to be divided by methods, which are not exact.Now up to the mass / kilogram, that's also different. The current definition by means of an artifact is exact.Anyhow, this unit is not invariant, as the prototype kilogram and its 40 copies all drift over time, obviously.The realization of the mass, that means any multiples or fractions of the prototype kilogram, also is not exact, because at first, it's only possible to make a direct comparison to the prototype by balances, which have about µg uncertainty, and the creation of fractions like 500g or 100g is even less precise, because there's no such precise 'ratio machine' for masses. Realization of an ounce is even worse, due to the non-exact conversion factor.Analogously, before the discovery of the Josephson Junction, ratios of the Volt depended on the Kelvin-Varley-divider (Fluke 720A), or the Hamon-divider (Fluke 752A), ratio uncertainty > 1E-7 only.The new kilogram definition by means of an exact value for Plancks constant, and the Avogadro constant will allow to make exact copies, and exact fractions and multiples, as comparisons to artefacts are no longer necessary.You may simply design a Si-sphere to let's say 125g, and determine its exact (currently to ~2E-8 uncertainty) mass by counting its atoms.In a similar manner, the Watt balance also allows exact creation or measurement of random masses by appropriate variation of its measuring voltage.This is the 2nd reason and advantage of the new mass definition with SI-2018.Frank

author: CJay
author_rank: Super Contributor
timestamp: May 11, 2017, 09:44:00 am
content: Quote from: TwoOfFive on May 10, 2017, 07:57:55 pmNope, we're all metric here apart from our speed limits and road lengths.Only ten minutes ago I was looking at a sheet of plywood that was 2440x1220mm and 12.7mm thick. Or, as everyone knows it, an 8 by 4 sheet of half inch ply.We might use metric units but an awful lot of stuff is just Imperial sized.'Gas' though, I doubt you'd be able to buy anywhere in the UK in gallons, partly because it's not legal to sell in gallons and partly because it's so damn expensive (~£1.20 a litre, roughly $7 an imperial gallon) and it looks cheaper in litres.

author: Nusa
author_rank: Super Contributor
timestamp: May 11, 2017, 10:33:53 am
content: And then there's dimensional lumber, which has changed sizes over the last century while retaining the same names. For instance, a 2x4 now actually measures 1 1/2" x 3 1/2". When I was a kid, they measured 1 5/8 x 3 5/8. Salvaged 2x4's from hundred year old houses are often actually 2" x 4" (and of superior old-growth wood that you can't get anymore).Lowes lost a lawsuit a few years ago for failing to put actual measurements on their 2x4s. I remember they paid out $1.5 million and updated all their labeling. I suspect some other suppliers did the same to avoid the same fate. Apparently just because it's a industry standard doesn't satisify consumer laws on accurate labeling.

author: CJay
author_rank: Super Contributor
timestamp: May 11, 2017, 11:08:21 am
content: On a product that changes size depending on how much moisture it has absorbed?That sounds like a minefield.

author: Ampera
author_rank: Super Contributor
timestamp: May 11, 2017, 02:48:47 pm
content: Quote from: CJay on May 11, 2017, 09:44:00 amHoly shit. 7$ a gallon? 3$ is expensive where I live. People were dying when it was a little over 4 dollars. It's even worse when you consider that in the UK, a gallon is around .8 of a US gallon.Quote from: tautech on May 11, 2017, 03:51:32 amIsn't it volume? 1 US Gallon = 231 cubic inches.

author: CJay
author_rank: Super Contributor
timestamp: May 11, 2017, 02:51:54 pm
content: Quote from: TwoOfFive on May 11, 2017, 02:48:47 pmNope, other way round, a US gallon is 0.8 Imperial gallons, ours is 4.55 litres, yours is 3.785 litres so it's not quite as painful. (still bloody expensive though)

author: Ampera
author_rank: Super Contributor
timestamp: May 11, 2017, 03:48:18 pm
content: Quote from: CJay on May 11, 2017, 02:51:54 pmrip.I've been studying for a maths final (Calc 1) and I still can't do maths.

author: CJay
author_rank: Super Contributor
timestamp: May 11, 2017, 03:54:54 pm
content: Quote from: TwoOfFive on May 11, 2017, 03:48:18 pmKnow the feeling well, the more I learn the less I know

author: iainwhite
author_rank: Unknown
timestamp: May 11, 2017, 03:55:20 pm
content: Quote from: tautech on May 11, 2017, 03:51:32 amIt is based on one of the gallons used in England in the 1700's - the 1706 Queen Anne Wine gallon. (there were others e.g. Ale gallon, Corn gallon)The UK 20-ounce gallon was not adopted until 1824 (based on the volume of 10 Avoirdupois pounds of water at 62°F) which was after US Independence.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 11, 2017, 04:28:27 pm
content: Quote from: CJay on May 11, 2017, 09:44:00 amWOW. That is really mixed up. You can still buy half inch plywood. Here in the US we get the plywood in 8 by 4 sheets, but it is usually 12 mm thick, labeled as 15/32. Looking at the web the plywood industry has generally standardized on metric thicknesses, with length and width most often conforming to the 8 ft by 4 ft size.So in a metric country you get your plywood in a weird fractional thickness which corresponds to a simple English system fraction, while in a English system country we get our plywood in a weird fractional thickness that corresponds to a simple metric thickness.Us tree descended apes go to great lengths to make things confusing.

author: Monkeh
author_rank: Super Contributor
timestamp: May 11, 2017, 04:32:16 pm
content: Don't mind CJay, the nominal thickness is a whole number.

author: Galenbo
author_rank: Super Contributor
timestamp: May 11, 2017, 05:08:09 pm
content: Quote from: CJay on May 11, 2017, 09:44:00 amIn our country, only cheap rubbish wood has that size.Decent quality is always 2500x1250 or 2600x1250.

author: Monkeh
author_rank: Super Contributor
timestamp: May 11, 2017, 05:09:39 pm
content: Quote from: Galenbo on May 11, 2017, 05:08:09 pmIn your country you never had an imperial infrastructure.

author: tronde
author_rank: Frequent Contributor
timestamp: May 11, 2017, 05:33:09 pm
content: Quote from: Galenbo on May 11, 2017, 05:08:09 pmI guess the 2500 and 2600 makes a perfect fit to your normal ceiling height in rooms? All countries have traditionally had different heights and therefore different sizes to minimise cutting.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 11, 2017, 05:45:57 pm
content: Quote from: Galenbo on May 11, 2017, 05:08:09 pmThese need to be sizes that chippies can work out when their brain is still working in imperial. Youngsters learning from the old guys end up working in inches too when being trained. It's a cycle that repeatsad infinitumso in likelihood will die only when wood working dies. Or whatever other industry.It's different when it comes to exporting though - there everything has to be standardised one way or another or shit hits the fan.

author: SeanB
author_rank: Super Contributor
timestamp: May 11, 2017, 06:39:49 pm
content: I get Chinese made stuff that has fasteners in there that have a metric thread size and pitch, but the head is not a metric size, but a US standard size, so that to assemble the kit i need a 14mm spanner on a M8 bolt, instead of the correct 13mm spanner. Some even have you needing a 14mm spanner for the bolt and a 13mm spanner for the nut, on a M8 standard pitch fastener. Then you get the M10, which can have either a 17, 18 or 19mm head, instead of the required 17mm. Metric socket sets almost invariably do not come with an 18mm socket, though I did get a few Imperial size sockets to compensate there, as they do prove to be quite useful, though there is a difference between 3/8 BSW, 3/8 AF and 10mm AF sockets, but 2 are nearly interchangeable, while the one is definitely not.Then cursed the manufacturer who decided they would make every fastener a 1/4 BSG thread, forcing me to use up those hard to get 10/24UNF recoil inserts.

author: metrologist
author_rank: Super Contributor
timestamp: May 11, 2017, 07:19:14 pm
content: This too...

author: tautech
author_rank: Super Contributor
timestamp: May 11, 2017, 07:46:28 pm
content: Quote from: iainwhite on May 11, 2017, 03:55:20 pmThanks, so if this is correct it might seem the earliest Yanks only had empty grog measures on which to do their liquid measurements which has remained unchanged to this day.How many 100's of years is that ?Time for change one thinks.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 11, 2017, 08:18:33 pm
content: Quote from: Galenbo on May 11, 2017, 05:08:09 pmDo you know why those dimensions instead of say 2000 x 1000 or 2500 x 1500? The first dimension pair makes sense in that you can line up two sheets on their side with a vertical one, but 2600x1250 will always lead to scrap.

author: Cerebus
author_rank: Super Contributor
timestamp: May 11, 2017, 11:25:14 pm
content: Quote from: CatalinaWOW on May 11, 2017, 08:18:33 pmIn general in modern construction in the UK everything comes in 600mm multiples as a basic unit with occasional 'half sizes' like 900mm. For example, kitchen cabinet and appliance sizes fit this model, so do window frames. Wooden sheet materials come slightly oversize to allow for trimming off the inevitable damage on the edges; drywall comes in exact sizes.Of course this is all pointless as most housing stock pre-dates any kind of standardisation. In our Victorian house it's a pleasant surprise when I find a corner that's actually square and I don't think any two walls in the house are the same length. Dry lining out living room a few years back involved me in way more trimming of sheets of drywall (plaster board) than is good for a man's temper.

author: tooki
author_rank: Super Contributor
timestamp: May 12, 2017, 04:35:11 am
content: That's the European 60cm standard for kitchens, been around for decades.Switzerland used to use a 55cm standard, so older kitchens were built to it, and replacement appliances are far more expensive than the 60cm appliances that can be sold in dozens of countries instead of one... (New kitchens are built to the 60cm standard now.)

author: Jeroen3
author_rank: Super Contributor
timestamp: May 12, 2017, 05:33:51 am
content: The same applies topaper sizes. Most of the world uses a dividable size with ratio ?2. But instead you can also use some arbitrarily chosen 215.9 by 279.4 mm, which does not divide without losing ratio.

author: yada
author_rank: Frequent Contributor
timestamp: May 12, 2017, 07:04:00 am
content: Quote from: moz on May 11, 2017, 05:13:23 amPV=nRT also so many people watch that channel that I'm sure if they were wrong they would have corrected it.

author: tszaboo
author_rank: Super Contributor
timestamp: May 12, 2017, 09:00:42 am
content: Quote from: CJay on May 11, 2017, 02:51:54 pmI know for a fact, that people in the USA dont realise how cheap fuel is there. They live in a dream, and keep thinking that it is very very expensive, and it should be a lot cheaper. Becuase they tank it into their Ford F150 with 3.5L EcoBoost V6 engine.Right.EcoBoost.You can just feel the trees blooming and chipmunks dancing in joy, when those "average murican" 2.5 ton monstrosities floor it.

author: CJay
author_rank: Super Contributor
timestamp: May 12, 2017, 11:06:45 am
content: Quote from: NANDBlog on May 12, 2017, 09:00:42 amAt today's exchange rate and fuel price, an American gallon would cost $5.84, yeah, they don't know how good they have it.There was a time when it was possible for a resident in the southeast of England who smokes to drive their car onto a ferry at Dover, drive off at Calais, cross into Belgium and fill their tank, do their weekly shop, buy their tobacco, then drive home and have saved money over what it would have cost to go to their local supermarket.It's probably still cheaper and with the potential of us leaving the EU, it's probably going to happen again (I was lead to believe the low prices of cross channel ferries were something to do with duty free sales, certainly got more expensive to sail when duty free on ships was stopped.)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 12, 2017, 11:11:35 am
content: Well, the US would grind to a halt if gas were that expensive. Europeans often have a hard time realizing how massive the country is -- I can drive four hours and get to thenext state border. Not the next country, not the ocean, just the next state over. Now repeat that a dozen times across the breadth of the country!No, most miles aren't spent going cross-country*, but the fact is, those of us who can afford to live in the suburbs and commute into work, do so because it's cheaper and it's better. Costs in metro areas are exorbitant (2-3 times or more), and we have plenty of space to spread out into, so we do. (The Houston metro area is half the population and three times the land of the London metro area!) Unless you live in the heart of the city (and like it that way, and you secured a job and housing in the heart of the city that you're able to balance a budget on), it's almost impossible to work without a car.*Actually, I don't know offhand what fraction of total road miles come from freight/trucking/commercial. Probably a reasonable fraction, but not a dominant fraction. (Anyway, that's vital, too, and not something that can be solved with rail or shipping.)A punitive gas tax would also unfairly punish the poor, as is the general problem with flat taxes like that.In contrast, Europe has significantly higher density, both in the density of population centers, and how closely spaced those centers are: this makes high speed rail an excellent investment (whereas it's a boondoggle almost everywhere here), and makes it possible to levy huge taxes on fuel there.(That said, there are also tremendous subsidies, credits and breaks going towards fuel producers. But that bleeds more into the sheer power politics of energy products which are critically vital to both civil and strategic purposes, so we don't need to discuss that here.)Tim

author: Cerebus
author_rank: Super Contributor
timestamp: May 12, 2017, 12:10:36 pm
content: That argument is something like a self fulfilling prophecy (I'm sure there's a technical name for this kind of argument, but it escapes me at the moment). You're essentially saying 'gas has to be cheap because we're so spread out' when an at least equally valid argument would be 'you're so spread out because gas is so cheap and therefore you're profligate with it'. What did you lot do before everybody had a car? Presumably the same as everybody else, lived within walking/horse buggy distance of where you worked.I'm afraid reminding us Europeans how big 'merica is sounds, in this context, like an appeal to exceptionalism. We know how big the USA is, approximately 6% of the world's land mass, containing around 4.33% of the world's population and using about 18.7% of the world's energy consumption. The latter imbalance being much more germane to a discussion of US gas prices versus elsewhere than the overall size of the USA.Talking of distance and burning gasoline; there was an item buried in one of the current affairs programmes here about the effect of 'brexit' on disrupting supply chains. The example they picked of an 'at risk' British company was one that manufactures an (automobile) engine component that starts life in the UK, gets trucked to Germany for one additional operation (honing, hardly a hyper-specialized operation), then France for another, then back to the UK for finishing before it is finally sent to a French owned plant in Portugal for assembly into a vehicle. That doesn't sound like a disruption, it sounds like an opportunity to rationalise an insanely inefficient supply chain, utilizing so much wasted energy for transport that makes any complaint I might have about American energy profligacy pale by comparison.

author: tszaboo
author_rank: Super Contributor
timestamp: May 12, 2017, 12:11:15 pm
content: Quote from: T3sl4co1l on May 12, 2017, 11:11:35 amI can drive for four hour on a friday near rush hour and do a grand total of 150km. I work 25 km from home, and it takes me 35-40 minutes to go to work. More if I take the highway.I've been to the USA. I realize, it is just impossible to go 1km without a car, just because there is no sidewalk or crossing, or the temperature might be so that you just die halfway, in the "business casual" clothing. Also, we should factor in that USA fuel is crap quality compared to what we have here, less power in the same quantity.My criticism is not towards cars. Its towards the excessively big, environment unfriendly cars that is the norm there. You dont need a 2.5 ton monster to get to work. Its is just unnessesary. And they do almost zero effort to get rid of them. With Trump, I think they actually gonna give government incentives for V8 and V12 cars.I drive a reasonable hybrid, and I pay some 500 eur road tax yearly. It is based on engine displacement, and emissions. USA? Road tax, if any, value of the car. Couple that with the cheap fuel, and you have low efficiency "make it as cheap as possible" cars which damage the environment. Our system is not perfect either, it makes diesel the preferred fuel. You see my point? Fuel is finite, I think even your president would agree with that.

author: Jeroen3
author_rank: Super Contributor
timestamp: May 12, 2017, 12:30:59 pm
content: Quote from: NANDBlog on May 12, 2017, 12:11:15 pmIf I drive 4 hours on Friday I'm either in Belgium, France, Luxembourg, halfway Germany or Limburg. It would cost me $45 on fuel.You can't go 1km, but you can go 0.621371192 miles

author: CJay
author_rank: Super Contributor
timestamp: May 12, 2017, 12:43:11 pm
content: Quote from: Cerebus on May 12, 2017, 12:10:36 pmnailed it, all the things I was thinking in one post.

author: macboy
author_rank: Super Contributor
timestamp: May 12, 2017, 01:01:00 pm
content: Quote from: TwoOfFive on May 10, 2017, 08:24:41 pmRoad signs would need to change, that is a huge one. But it is still a poor excuse. Imagine all the jobs created for the road sign manufacturers and people to install them! (only half joking).But all the other things like lumber, tools ... no. Canada has been officially completely metric for 40 years, and though our road signs are in kilometers, we still use e.g. 2x4's, #8 screws, and 1/2" drive ratchets. The only measuring cups in my kitchen are in cups, Tbs, tsp, etc. When I buy apples, they are $1.49/lb. If I saw a metric price on produce, I'd have to do the math in my head to figure out if it was a good deal or not. Beer is sold in cans marked 473 ml, but you order a pint at the bar. I think you will find a very similar situation in the UK, which is also "officially" metric but people hang on for dear life to the old system wherever they can. The mindf**k in Canada is that we had used the imperial system, not the US one, so we still run into weirdness over things like the size of a gallon (and therefore MPG ratings on cars) being completely different from our neighbors.As for the hilarity of the US system being based on metric, I don't get that.Of course it is. It has to be.Everyone needs to refer to a common standard (even if converted to different units at times) so that trade is possible.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 12, 2017, 03:33:21 pm
content: Until the first time I traveled to Europe, I never appreciated my mother's statement: "In Europe, 100 miles is a long distance, and in America 100 years is a long time." I still marvel at how the UK can squeeze three or four countries into an area slightly less than my state (Oregon). I strongly suspect that if the USA had similar packing density, our transportation infrastructure would have evolved along similar lines to Europe.

author: BrianHG
author_rank: Super Contributor
timestamp: May 12, 2017, 03:53:11 pm
content: Quote from: macboy on May 12, 2017, 01:01:00 pmCareful with some grocery stores which have an organic food section here in Quebec. They play the trick of pricing the regular oranges at $1.27/kg, but, price the adjacent organic versions at $1.47/lb. You may think the organic is only 20cents more, but, they are screwing you almost 3 fold. Worse, when the oranges are in season, they are potentially the exact same. I finally noticed when the 2 versions were priced 1cent apart one weekend & finally saw that they used different measurement systems.

author: boffin
author_rank: Unknown
timestamp: May 12, 2017, 04:39:25 pm
content: Here in Canada we have the odd combination of metric and imperial. Example, produce is sold in kgs at the till, they're most often shown on the shelf in $/lbTechnically all legal measurement is in metric, the roads are signposted in metric (since the late 70s), buy fuel in litres etcHowever, the problems of adapting existing imperial things to metric means there are issues still. Building materials are almost all still in imperial, houses are build with studs 16" on centre etc etc. Copper pipe is 1/2", 3/4", conduit is in inches and lots of stuff like that. Most fasteners are also still imperial, and for added confusion, most wood screws use a Robertson (square) head in Canada.However, still my favourite example of the mix of metric and imperial is the 4' x 8' x 19mm (yes that's how it was marked) sheet of plywood I saw in Home Depot.

author: Cerebus
author_rank: Super Contributor
timestamp: May 12, 2017, 04:40:44 pm
content: Quote from: Richard Crowley on May 12, 2017, 03:33:21 pmLots of Londoners, lots of Parisians, lots of occupants of most European cities, daily pass buildings that pre-date any European setting a single footanywherein Continental America without giving the age of the building a first, let alone a second thought. The LondonsuburbI live in has more than a few buildings that pre-date Queen Elizabeth - the first Queen Elizabeth, obviously.

author: TimFox
author_rank: Super Contributor
timestamp: May 12, 2017, 04:42:44 pm
content: With respect to land measurement:In 1959, the United States officially went metric, but didn't tell anyone.An important change was to change the inch from the old definition (1 meter = 39.37 inch) to the current definition (1 inch = 2.54 cm) to agree with the British definition.However, rather than change every single land-tenure document in the entire country, a new unit was defined: the "U.S. Survey Foot", which uses the older definition of the inch and is the basis for all our land deeds. This sounds trivial, since the difference is only 2 ppm, but it adds up.Exercise for the reader: calculate the absolute difference in area between two "sections" (1 section = 1 sq. mile) measured using the two definitions.

author: tronde
author_rank: Frequent Contributor
timestamp: May 12, 2017, 04:59:44 pm
content: I don't understand why people make lumber a problem?Norway used inches for lumber at least in the 1960s. Today we call a 2x4" for 48x98mm because a dry 2x4" measured very close to 48x98mm. What is the poblem? Going metric does not mean you need to call it 50x100mm, and the precision of lumber is not close to 1/10 of a millimeter.

author: mib
author_rank: Contributor
timestamp: May 12, 2017, 05:10:54 pm
content: Some people seem to get very upset by mixing of units, like a 1.8m 2x4... But I tend to think of it as multiples of "wood units" which happen to be 25mm.Realistically, it's just a shortcut to deal with the one real problem with metric measurements, which is that the words just don't roll off the tongue in English."I'd like a six foot two by four" is so much easier to say than "I'd like a one point eight meter length of one hundred by fifty millimeter"

author: Ampera
author_rank: Super Contributor
timestamp: May 12, 2017, 06:19:05 pm
content: Quote from: NANDBlog on May 12, 2017, 12:11:15 pmNot sure what part of the US you've been in, but I can walk from Schenectady to Albany 18 miles without any road troubles. This is NY, so the sidewalks may vary.Heat is another matter. In the summer we get 80-100F (27c-38c) and temperatures I've seen as low as -20F (-30C) (VERY rarely) with a standard of around -5F to 20F (-20c to -7c) in the winter. Don't forget the feet upon feet of snow. (3ft is a bit less than a meter)Quote from: macboy on May 12, 2017, 01:01:00 pmIt's not just changing road signs. While all of our cars do have KM dials on the speedometers, you would have to spend a nice amount of money re-certifying all the brick for brain drivers we have to work with kilometers. Not only that, but in the US we have special markings for highways. There is a peg every so often based on our mile system. That would need to be re-done.For Canada you could make the excuse that it worked for you, but you have 10% of our population, and last I checked, you don't have highways throughout your entire country, whereas we have 164,000 miles (263932 km) of highways in the US. Our interstate system is one of the largest in the world, and it ALL is marked, designed, and recorded in miles. Remarking, resigning, and reordering all of the 164,000 miles of highway would be UNIMAGINABLY expensive.And that is just highways. There are in total 4.12 million miles of roads in the United States.Let that sink in, 4.12 million miles can go around the earth over 165 times. And ALL of it would have to be re-marked, re-signed, and re-mapped.Canada has 647,700 miles of road. Which is a HECK of a lot less than we do, and I'd wager that you have more now than you did when you switched to metric.Understand that the US is MASSIVE. We are number three in population and size. We have around 350 million citizens, and we have 3,717,727 square miles of land. Unless you live in Canada, Russia, China, or India, we have more land and people than you do. We can't just switch that easily.

author: Cerebus
author_rank: Super Contributor
timestamp: May 12, 2017, 06:20:02 pm
content: Quote from: mib on May 12, 2017, 05:10:54 pmExcept you'd never say that, you'd say "2 metres of five b' ten ", just as you would say "two b' four ".Only someone who didn't naturally use metric units would specify something as variable as wood by millimetres. Using millimetres for wood is like using 1/32nds of an inch for wood, only a luthier or veneerer would think of stock in those kind of sizes.

author: Cerebus
author_rank: Super Contributor
timestamp: May 12, 2017, 06:45:10 pm
content: Quote from: TwoOfFive on May 12, 2017, 06:19:05 pmYou're also the richest nation, like to believe that you're the smartest and pride yourselves on an "American can do attitude". You ought to be able to do it if you wanted to, so the appeal to being "MASSIVE" (frequently another American point of pride) is a poor excuse.The actual truth is that you don't need to change the road system to metric to metricate everything else, we haven't in the UK despite making metric units the "official" unit for everything. We just decided to quietly stick to miles for roads, pints (proper full size ones) for beer and barleycorns for shoes while simultaneously switching everything to metric and changing to a decimal currency system at the same time. We managed it after using Imperial units since "time immemorial", you've only been at it for a bit over two hundred years yet you're more stuck in your ways than us fuddy-duddy Limeys.

author: Nusa
author_rank: Super Contributor
timestamp: May 12, 2017, 06:49:21 pm
content: Quote from: tronde on May 12, 2017, 04:59:44 pmAn excellent illustration of the issue. Your dry 2x4 is 48x98mm. The dry 2x4's I can buy are 38x89mm. If one was to ship between countries, the difference in dimensions would be a real issue if all the order specified was "2x4's".QuoteSure we could, if the public were willing to CHOOSE to do so. There would have to be some pandering to the older generations for a while, such as dual-unit highway signs. Politically it isn't viable to do it overnight....people are too resistant to change, so it's been happening slowly instead.In many areas we've already done a stealth switch. For instance the entire food industry almost universally has added metric units to labeling, and some things are even sold based on whole metric units. The two-liter soda bottle was introduced in the 70's, for instance.

author: karoru
author_rank: Regular Contributor
timestamp: May 12, 2017, 07:23:38 pm
content: Quote from: Cerebus on May 12, 2017, 06:45:10 pmWhich reminds me of case of Polish pub in UK being threatened by £2000 fine because they were selling Polish beer in Polish glassware (0.3L and 0.5L) and apparently you can serve beer and cider only by pints:)

author: metrologist
author_rank: Super Contributor
timestamp: May 12, 2017, 07:35:01 pm
content: Quote from: CJay on May 12, 2017, 12:43:11 pmGuise? I found some data. Is it valid? I think it says that Iceland and Canada consume more energy per capita per annum (2014) than the US. I know, mostly for heating I'm sure...https://en.wikipedia.org/wiki/List_of_countries_by_energy_consumption_per_capitaHere is another source that puts China's total energy consumption at the top.https://yearbook.enerdata.net/That's not to say that the US is not using some of the world's energy. I hope most of it is being used wisely...

author: Towger
author_rank: Super Contributor
timestamp: May 12, 2017, 08:46:48 pm
content: It is much easier to convert your speed and distances from miles to kilometres than you think. We did it in 2005, and it took about a week before all road signs and speed limits were changed. It is not as if you need dedicated teams working for years. Each area will have its own preexisting road maintenance staff. You just need a proper survey of all signs before to hand and their equivalents ready. The actual changing of them does not take long. We actually ended up with far better signage. Speed limits convert up or down to their closest equivalents. E.g. 30 mph = 50 kph, 40mph = 60 kph and 80 mph = 130 kph etc.

author: boffin
author_rank: Unknown
timestamp: May 12, 2017, 08:57:43 pm
content: Quote from: TwoOfFive on May 12, 2017, 06:19:05 pmComparing USA to CanadaGDP 18569b / 1529b 8.2%Pop 325m / 36.5m 11.2%Roads 4120k / 648k 15.7%By your logic it would be easier for the United States, given fewer miles of road per person, and more GDP per person.Canada has only 11% of the population and 8% of the GDP, but nearly 16% of the roads compared to the USA.It's simply a myopic "why should we have to change" that the US has. As the world economy is more controlled by Asia and a unified Europe, the USA will become increasing isolated by sticking to imperial.

author: Cerebus
author_rank: Super Contributor
timestamp: May 12, 2017, 09:43:36 pm
content: Quote from: metrologist on May 12, 2017, 07:35:01 pmIceland - population 0.0045% of world, energy usage 763.44 GJ per capita per annum, total energy usage 259 PJ (53.4% from geothermal, 17.2% hydro so a poor comparison to other countries on a straight GJ per capita basis, also ****ing freezing)Canada - population 0.487% of world, 302.49 GJ per capita per annum, 11,051 PJ totalUSA - population 4.33% of world, 290.47 GJ per capita per annum, 94,390 PJ totalChina - population 18.4% of world, 93.50 GJ per capita per annum, 129,321 PJ totalSources:https://en.wikipedia.org/wiki/List_of_countries_by_energy_consumption_per_capita(from above),https://en.wikipedia.org/wiki/List_of_countries_and_dependencies_by_population

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 12, 2017, 09:49:55 pm
content: Quote from: karoru on May 12, 2017, 07:23:38 pmYes, we're very strict with units of alcohol. And for good reason. Pubs and clubs have been caught using undersized shot measurements. And when it comes to ordering cider and beers and so on, from the tap, you are expecting a pint (either half or multiples when it comes to jugs).If it's from a bottle, the volume should be on the menu or clear that it is bottled and be poured in front of the consumer.

author: Gyro
author_rank: Super Contributor
timestamp: May 12, 2017, 09:53:50 pm
content: Happy indeed is the man who can get 53.4% of his energy from geothermal and 17.2% from hydro!Well, apart from the odd eruption anyway!

author: Cerebus
author_rank: Super Contributor
timestamp: May 12, 2017, 11:59:19 pm
content: Quote from: RGB255_0_0 on May 12, 2017, 09:49:55 pmYou can do many things to an Englishman and get no stronger response than "Steady on old chap!" unless you, in rough order of importance, most serious offence first:-Mess with our beerMess with our familiesInvade a neighbouring countryWalk into a pub and loudly declare in an American accent how you "Saved your arses in WWII"Any of the above are regarded as a declaration of your love of hospital food and, being obliging and brought up to help when we can, we'll offer you the opportunity to sample some (unless you do the fourth in a pub near Aldershot*, when you will simply be posted back to your relatives in a small envelope).To the Englishman, and most Britons, beer is a very serious and important matter, one that makes tea look trivial in comparison.*This is roughly the equivalent of walking into a bar in Quantico and shouting "All Marines are pussies!".

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 12, 2017, 11:59:57 pm
content: Yes it would be difficult for us in the US to change to metric, and yes we have the resources to do it if we wanted to.The real question is why it is so important for some of you living in other countries for us to change? I think if you answer that question you will also have the answer to why we aren't as motivated as you would like.For me, I would prefer to be metric, but don't find it one of life's urgent problems. I have tools to measure and work in both systems and do so on a regular basis. In topics of primary interest to this forum one of the most serious difficulties of having mixed systems is that when designing PWBs using parts whose native dimensions are in two systems the software can be more complex, and the results may not be as pretty. I don't write PWB software so can't get too concerned about the first point, and have never been obsessed with the beauty of my PWBs. This attitude started when laying them out with Rubylith and automation has not made that attitude change. The electrons and fields are generally totally ignorant of the measurement system.

author: moz
author_rank: Regular Contributor
timestamp: May 13, 2017, 12:43:28 am
content: Quote from: CatalinaWOW on May 12, 2017, 11:59:57 pmThe USA spent $125 million dollars making a crater on Mars because they're too proud to switch:mars climate orbiter. That is an unusually dramatic example of problems that happen all the time.I periodically experience the problem of fasteners that fit but don't have any real strength because they're one of the multitudinous imperial sizes mismatched to a metric other half. Or worse, they're one of the Chinese or Indian "imperial thread cut to a metric size", like the 5mm x 24tpi BSF bolt I found the other day. It's almost a 3/16th bolt, except it won't fit into a 3/15th nut, and it fits but loosely into an M5x0.1mm metric nut. Obviously you can't tighten it into the metric nut to any useful degree. Then there is the "Made in the USA" problem. Anything the US exports is likely to contain at least some imperial-measurement items, making them impossible to repair outside the USA. Oddly, the rest of the world sees no benefit to having8 parallel size sets of fasteners, we get grumpy enough when something uses metric fine for no good reason.To people who use metric systems it seems more like a case of "why stick with something almost everyone agrees is horrible?", and the typical answer "that's how we do things in the USA".

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 13, 2017, 02:46:30 am
content: Quote from: moz on May 13, 2017, 12:43:28 amHow do you get 8?In common fastener use, we have 1 or 2 choices: fine or coarse. (I'm sure you'll be embarrassed to hear there are fine metric thread standards too.)Those are the "regular" ones, and everything else is "special". Of course, there are standards to cover the most common ones: large shafts with fine threads (like potentiometer shanks, lamp stem and such), pipe threads (usually tapered, and I guess British ISO pipe thread resembles, or equals, NPT?), and other things. I see reference for tapered and straight metric threads, but I can't tell how common they are in practice.Whitworth has been completely superseded (since almost a century), and is only practiced by machinists doing restoration -- because they have to.You may be shocked to hear there are still other thread forms: Acme comes to mind (a nearly square thread form, used for axial load bearing threads, in clamps, screw jacks and such).Indeed, there may be more metric than imperial thread standards, in total. Because more and more applications for the lowly screw are constantly being developed, and the most popular dimensional basis will naturally get the most add-ons. (Why should that be embarrassing?)Tim

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 13, 2017, 02:54:45 am
content: Quote from: moz on May 13, 2017, 12:43:28 amThey 125 million dollar crater was because people on both sides of a software interface made assumptions instead of checking. As I pointed out earlier, similar errors can and do happen within both measurement systems (assuming a kilo or milli for example).Badly made bolts and nuts can be found within any system if you buy cheap.While you point out the horror of eight parallel size sets there are really only two, the other six are specialty specifications which have to be purchased special order and are only used in situations requiring them. There might be some small savings from using these instead of a full custom design. In the metric system all of those specialty situations (they do exist, but it may not occur to someone who specializes in electronics) are custom designs. In the US system (and I would presume in the metric world) there have been failures analogous to the mars crater when some repair technician replaced one of these specialty grades with one of the two primary standards.I have both metric and English tap and die sets. These sets are made to cover the most commonly used sizes. There are the same number of sizes in both sets. But for some reason I more frequently need yet another size or pitch on the metric side. Comparing the simplicity of the fastener systems is more complex than counting the number of standards.Calling out a fine thread pitch (either metric or English) is much like specifying matched transistors, or a controlled temperature coefficient. If you get grumpy when they are necessary you perhaps should be chasing the other low cost producers down to the poor fit and function bottom. If you are grumpy because you have the option of making the choice you are choosing a different path to the same place.I agree with your point about buying US products and finding them difficult to repair with local materials. The solution is simple - don't buy US products. If enough of you make that choice it might force us to switch. Of course the reciprocal situation also exists (although it is unlikely to result in a change away from the metric system). While we are pondering that possibility, think about this - from your point of view their are two things wrong with the English system. First - it is complex and has some built in inconsistencies (confusion between pound force and pound mass for example). Second - for most who seem to care it is not the system you grew up with and is therefore unfamiliar and strange. Looked at from our point of view there is an advantage to the metric system perceived mostly by scientists and engineers, but the second problem applies just as strongly.

author: Ampera
author_rank: Super Contributor
timestamp: May 13, 2017, 03:50:48 am
content: The US has more money than everybody else, but we also spend more elsewhere than everybody else.We are also around 20 trillion USD in debt, which has got to be setting some world records at this point.And I am not saying we couldn't. As said, we spent more money making a hole on another planet, launching more nukes than the rest of the world combined, and throwing more at our military than the next five countries combined, but that's also the reason why we it would be a big burden on us, because we spend that on everything else.Ironically we spend f all on our roads. I live in a place where it's alright, but in some parts of the US the line between dirt road and paved road is almost non-existent.EDIT: I do also want to state that I am by no means in a position to accurately gauge if we can or should afford it. This is just self theory.

author: vk6zgo
author_rank: Super Contributor
timestamp: May 13, 2017, 04:26:19 am
content: Quote from: T3sl4co1l on May 13, 2017, 02:46:30 amActually Whitworth is alive & well in India, & because they are so cheap, are exported in container loads to Oz.If you go into one of our large Hardware stores , like Bunnings, you will find a huge rack full of galvanised Whitworth bolts & nuts, & a very much smaller number of Metric ones.If you are just bolting a pergola, or something like that together, it doesn't really matter.The thing that I always found annoying with small US "imperial" screws was that they were not Whitworth/UNC, or UNF, or anything else that was made outside North America.British BA screws were nearly as annoying, but we could actually buy them, whereas any spare ones of the iype used in Tektronix equipment were lovingly stored, & you almost had to beg for them.I always though it would have been "a nice little earner" to import a bundle of those screws, but mainstream bolt suppliers didn't really seem to care.Of course, there were a plethora of weird thread standards, such as a "Lucas thread" on some early '50s starter motors ( my brother's Singer SM1500 was mostly made up with BSF,UNF & Whitworth, but none of those fitted the starter).My 1936 Chev had "GM" thread on the big nut that held the front wheel bearings & hubs in place.Not really on topic, but why, oh, why did classic Chryslers use LH threads on the left hand side wheel nuts/bolts?It seems that eventually, they realised that other manufacturer's vehicles weren't continuously losing wheels & stopped doing it.It seems like a classic case of a mistaken idea becoming so embedded in company thinking, that only "an enemy of the state" would question it!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 13, 2017, 04:57:32 am
content: Quote from: vk6zgo on May 13, 2017, 04:26:19 amI stand corrected!Obsolete in the civilized world, then. (And y'all Kiwis, just a bunch'a sheep shaggers, uncivilized the lot of 'em.)QuoteTektronix loved to make every little screw and nut a custom jobby, like those captive shoulder screws retaining the face surround on the Tek 475. What a pain!(I mean, at least those didn't go loose, but of any of the ones that can...)QuoteHad a coworker who previously worked at Harley Davidson -- he said every newbie's big new idea is, "hey, what if we do so-and-so to the engine, and improve emissions and fuel efficiency by 300%?" (Not exaggerating: their engines arethat bad!) The newbie quickly learns the lesson that one does not tamper with the heart of "That Harley Sound"...Tim

author: tautech
author_rank: Super Contributor
timestamp: May 13, 2017, 05:55:55 am
content: Quote from: T3sl4co1l on May 13, 2017, 04:57:32 amBe prepared to be again.vk6zgo is an Aussie.....yeah and we Kiwis think they are and the reverse applies for sure.

author: Ampera
author_rank: Super Contributor
timestamp: May 13, 2017, 06:25:08 am
content: Kiwis are tasty.The fruit, not the bird.Although, I have never had a Kiwi bird, so I wouldn't know. Anybody up for a taste of bald eagle? (Don't actually do this in America, you will be tried then shot, then shot again.)

author: SeanB
author_rank: Super Contributor
timestamp: May 13, 2017, 10:31:17 am
content: Back to the topic of cold places, Iceland has such a high energy consumption simply because they, along with South Africa, are the major refiners of aluminium. Despite the fact neither place has either the bauxite ( Australia) or the chryosite, they have massive smelters, simply because you need sodding great big amounts of electricity to electrorefine the aluminium out of the ore, rather than any other thing. Thus the ores are brought to the electricity, rather than the other way round.Kind of skews the figures when you are making 1 ton of aluminium per year per person for export, not that they are using it, it is just the combined energy generation for the year divided by population.

author: Gromitt
author_rank: Regular Contributor
timestamp: May 13, 2017, 11:47:31 am
content: Quote from: SeanB on May 13, 2017, 10:31:17 amAnd the fact there is only about 330 000 people living in Iceland.

author: Cerebus
author_rank: Super Contributor
timestamp: May 13, 2017, 03:29:54 pm
content: Quote from: SeanB on May 13, 2017, 10:31:17 amTucked away in the highlands of Scotland slightly to the north of Glencoe, in a place so remote you'll find nothing but the odd lost sheep, wild haggis, the occasional ghost of a MacDonald and a few folks walking the West Highland way is a 15 metre wide strand of pipes that appears out of the hillside and runs down to a hydroelectric power station in Kinlochleven where British Aluminium had a smelting works from 1909 until it was closed in 2000 by the then owner Rio Tinto. The power station is still there and provides power to another smelting works in Fort William and the 'company town' of Kinlochleven is reinventing itself as part of the tourist industry. The site of the former smelting works now hosts an ice climbing centre. The actual ore was dragged by barge up Loch Linne from the sea and then up Loch Leven.At one point every single erg of hydroelectric power produced in the UK was used for smelting aluminium, either in Scotland or in Wales.

author: CJay
author_rank: Super Contributor
timestamp: May 14, 2017, 09:14:39 am
content: Quote from: Towger on May 12, 2017, 08:46:48 pmchanging the signage, not a problem, changing the people, more of a problem though I guess a stepping stone would be to display dual unit signs for a period of time before slowly phasing them out.Sadly here in Great Britain we seem hell bent on being as awkward as possible and there is a loud and vocal minority who want to keep us in the past when it comes to things like our measurement units.

author: CJay
author_rank: Super Contributor
timestamp: May 14, 2017, 09:16:43 am
content: Quote from: Cerebus on May 12, 2017, 11:59:19 pmI say, steady on now old chap...

author: CJay
author_rank: Super Contributor
timestamp: May 14, 2017, 09:36:43 am
content: Quote from: CatalinaWOW on May 12, 2017, 11:59:57 pmI don't particularly care one way or the other as long as the measurement systems can be easily converted, as was demonstrated earlier with the confusion between Imperial and US gallons to litres it is a problem having separate and 'odd' systems.I personally don't give a damn which system is used but Metric is a very simple system and is 'powerful' enough to cover all uses where a measurement system is required, volumetric, dimensional, mass, weight etc. etc. so units can be easily converted between and still make 'sense', E.G. a kilogram of water is a litre of water and is 10x10x10CM volume, converting that between pints, gallons, inches etc is a mess and has so much scope for cock up even if you're working in the same non metric system.For day to day consumables, I suspect the units don't matter as long as you can afford to buy 'enough'.

author: Towger
author_rank: Super Contributor
timestamp: May 14, 2017, 09:41:49 am
content: Quote from: CJay on May 14, 2017, 09:14:39 amRunning two systems is far more confusing. It is actually easer to convert once you stop thinking in the old system. Another example was the euro conversation, it happened faster and much easer than people expected. Except in Italy who kept trying to keep their millions of delfated lira.

author: m98
author_rank: Frequent Contributor
timestamp: May 14, 2017, 10:19:27 am
content: Quote from: TwoOfFive on May 12, 2017, 06:19:05 pmSo what? At least modern retroreflective street signs have an expiration date after which they should be replaced. As you certainly don't have street signs for 4.12 million miles of road in stock, they're produced on demand. So where's now the issue to use Km on the new signs? After maybe 20-30 years you'll be all metric.

author: Cerebus
author_rank: Super Contributor
timestamp: May 14, 2017, 01:35:01 pm
content: Quote from: m98 on May 14, 2017, 10:19:27 amIn some states there's no possibility of road signs reaching their retroreflective 'sell by' date, they're too full of bullet holes way before that rolls around:Note that this picture isn't in the boondocks miles from anywhere, that's someone's house behind it! If that was a target on a full bore rifle range it would have a sandbank followed by a 2-4 mile safety zone behind it! That picture, by the way, is from the Federal Highway Administration's pages on sign maintenance. The section on repairing bullet hole riddled signs is written in exactly the same tone as the one below it on dealing with spray paint graffitti as if it's a minor everyday hazard with no thought of mentioning quite how insane this is.

author: Nusa
author_rank: Super Contributor
timestamp: May 14, 2017, 03:33:07 pm
content: Need a reverse angle to assess the safety aspect. Looks to me like all the shots came from the house area, not toward it.

author: rdl
author_rank: Super Contributor
timestamp: May 14, 2017, 03:52:31 pm
content: The fact that there are no other dwellings visible in the photo indicates that it might actually have been taken in the boondocks.

author: Cerebus
author_rank: Super Contributor
timestamp: May 14, 2017, 03:58:13 pm
content: Quote from: Nusa on May 14, 2017, 03:33:07 pmLike the direction matters? What looks like .30 calibre or bigger flying around near someone's house, either towards the house from the road the sign is on or vice-versa towards the road and you think there's a way it might be safe?

author: Cerebus
author_rank: Super Contributor
timestamp: May 14, 2017, 04:07:06 pm
content: Quote from: rdl on May 14, 2017, 03:52:31 pmLike it matters? Would the exact location somehow make shooting up a road sign anywhere, let alone near a residence a sane thing to do?

author: rdl
author_rank: Super Contributor
timestamp: May 14, 2017, 04:22:40 pm
content: Out in the country there are few restrictions on discharging firearms. I'd be willing to bet the residents of that home were the ones responsible for those bullet holes. At any rate, none of this has to do with Metric System standards.Here's an interesting fact about highway signs in the US:https://www.fhwa.dot.gov/interstate/faq.cfm#question17If an official signage change were to be done for the Interstate System, I wonder how the mile markers would be handled? Would they be replaced or just changed to decimal kilometers? There's tens of thousands of these so either way it wouldn't be cheap.

author: Nusa
author_rank: Super Contributor
timestamp: May 14, 2017, 04:49:27 pm
content: Quote from: Cerebus on May 14, 2017, 03:58:13 pmCertainly what's in the background matters. One house doesn't tell how many houses are in the area. What if the reverse angle looks like:Quote from: Cerebus on May 14, 2017, 04:07:06 pmWhat does sanity have to do with gun safety? I'll certainly agree it's illegal to shoot up the sign, but that doesn't necessarily make it unsafe or insane.

author: Cerebus
author_rank: Super Contributor
timestamp: May 14, 2017, 05:30:30 pm
content: Quote from: Nusa on May 14, 2017, 04:49:27 pmAs they say: "Only in America...".

author: NottheDan
author_rank: Frequent Contributor
timestamp: May 14, 2017, 06:01:48 pm
content: Quote from: rdl on May 14, 2017, 04:22:40 pmThe same way it has been done before elsewhere - as they crumble and the need for re-surveys comes up road-by-road they will be replaced over time with both system in parallel during the transition period.

author: boffin
author_rank: Unknown
timestamp: May 14, 2017, 08:16:02 pm
content: Quote from: Cerebus on May 14, 2017, 01:35:01 pmAs a kid we'd drive up and down I5, and I always remember the sign saying "no shooting within 1/2 mi of a rest area" was always full of bullet holes. Even as a 5 yr old I thought how ironic that was

author: Ampera
author_rank: Super Contributor
timestamp: May 14, 2017, 11:36:17 pm
content: This is an example of how guns should not be given to idiots.Unfortunately it's those same idiots who are in power, and who refuse to put in adequate gun control.I don't want guns to be illegal, and I want the right to own a gun to be available in every city in every state, but there needs to be a limit.

author: tronde
author_rank: Frequent Contributor
timestamp: May 15, 2017, 12:37:37 am
content: It seems like some of the US has turned to metric.https://safety.fhwa.dot.gov/local_rural/training/fhwasa09025/