Well to be fair, only Americans would specify inches nowadays.


Honestly, I can’t say I’m surprised.

Aside from the fact the overwhelming majority of the world doesn’t really use inches anymore, the international symbol for inch is actually in, so even places that do recognise inches probably don’t recognise the old-fashioned ‘double prime’ (). Odds are whoever read it thought that was a typo or some stray marks on the paper.


And Canadians :slight_smile: :canada: (though, we use a strange mix of imperial and metric)

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I guess so. Everything’s pretty much just the metric system here as far as I’m aware, but in various math textbooks I’ve found some of the questions using inches and miles and stuff (e.g. area, pythagorean theorem, converting, etc.), so maybe it is used quite often here.

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It’s interesting me that you don’t encounter imperial measurements regularly. Almost all construction plans and materials/fasteners, etc are in feet/inches, and most Canadians generally relay their height/weight in imperial as well (though our medical system now records in metric for these).

It seems, though, the younger you are here, the more likely you are to think in metric units first. This was an interesting wiki about our current usage tendancies here. Perhaps it’s regional as well - seems that Quebec, for instance, has a fuller adoption of the metric system than some other provinces.

I’m actually fairly adept at thinking ‘metrically’ for distance measurements, but I always feel like an outlier in this regard, and it’s mostly because of work in the automotive industry for a number of years, where everything was specced in metric.

Anyhow - I’m getting way off track :slight_smile: ! New Arduboys look great, and TIL that you can’t assume that internationally " is going to be understood to represent inches on drawing dimensions.


Lol it was a simple unit conversion calm down.


In practice so do Brits.

We started metrification in 1965 and technically ever actually completed it, so we’re in a weird state of heel-dragging limbo where children are taught (more or less) only the metric system, and all food and drink has metric units on the packaging, but the signs are in miles, petrol is sold in litres, people still measure their height with feet and inches and their weight in stone and pounds, and pubs still sell ‘pints’, but they’re probably only proper pints if they’re from one of the pumps - anything in a bottle is liable to be not-quite-a-pint.

(In contrast, Australia’s metrication was highly successful.)

I expect you have the same situation as Britain: younger generations are only taught metric units in school, but the older generations still frequently use imperial units because that’s what they were taught at school and were used to using pre-metrification, and whatever they learn about imperial units is through ‘osmosis’ - television, parents, other older friends and relatives, et cetera.

There’s a similar one for us.

I’d expect the French-speaking areas to have better adoption simply because France was the first country to go metric and is thus very strongly metric. (I presume France still has some degree of influence over French-speaking parts of Canda, if only through relatives and French-language media like books and film.)

(France actually started going metric in 1795, during the revolution, around the same time they attempted to scrap the Gregorian calendar - a feat which lasted all of 12 years before they gave up.)

I think even America uses the SI system for science and engineering pursuits now. There’s always been a very strong push for it in those industries.

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Don’t y’all use 3/4" and 1/2" drive sockets or do you have something different?

Also there are lot of “standard” or “imperial” measurements on pcbs most thing are standardize around the mil at least in track spacing. I’m not sure I’ve ever seen imperial measurements on a component footprint though.

That reminds me of a few other things. Here, signs are in kilometres, petrol is also sold in litres, and my family measures height with feet and inches (although, it seems like that’s sort of the standard for measuring height, no?) but one guy I know told me his height in centimetres when he asked me for mine, so I guess everybody here uses different things.

I’d guess “one millimetre” would just be way easier than like “1/8th of an inch” (or something). That sort of summarizes the whole imperial system haha.

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I had no clue what these were, but apparently we do. Apparently socket spanners are a weird edge case where metric equivalents are still quite rare. (I checked some Aussie sites too.)

Just to make a point though:

Inches and millimetres, side-by-side, and nobody here would bat an eyelid at that. You also get cases where the size is specified in both inches and millimetres (“(1/4″ – 6.35 mm)”), which I’m presuming would be even more common on the continent.

As far as I’m aware, screens are the only electronic component that still regularly get measured in inches. All other components should theoretically be done in centimetres and millimetres.

Just to bring it up: technically the US isn’t actually on the imperial system despite using many imperial units.

I thought we had a few signs that had both mph and kmph, but then I remembered what I’m thinking of are bridge height signs. Some of those have both metric and imperial, and others are just pure metric.

Apparently footpath signs can also sometimes be purely metric.
(There’s a decent list of other examples of metric signs here.)

Not in Japan. They definitely use centimetres (and maybe metres).
(And before they went metric, they had their own ‘shaku-kan’ system, which was based on China’s old system.)

Tentatively I’d say on mainland Europe they use metres and centimetres, but don’t quote me on that.

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Metrication in the United States - Wikipedia.

Did we paste this already? Congress said go for it in 1975 and in traditional american fashion everyone was like “you can have our miles over our dead bodies”.


Lol it had a logo


From what I understand most people in Europe still refer to fuel economy of cars in MPG despite using neither measurement.

Is there a third secret measurement system the illuminati uses and they aren’t telling us about?


The Illuminati still use the cubit from ancient Egypt :slight_smile:


As @Pharap pointed out, In Australia we have got rid of all imperial measurements - except for beer sizes. But these are a mess with some states including mine serving imperial pints (20 oz), some serving ‘metric’ pints (500ml), other serving schooners (15 oz) and one state (the one that @uXe lives in) calling a schooner a pint. I was there a few years back and got pretty excited when I saw a $6 happy hour of local pints. My excitement crashed the moment I realised they were calling a schooner a pint. What a rip! They are only 3/4 (or 0.75x) the size!


Most countries other than the U.S. use the metric system. You should consider this when specifying any type of measurement.

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Wait really?

(In Canada) I have equal amounts of both imperial and metric sockets and wrenches (spanners) in my collection. For tools, some have imperial scales and dials and others are metric but often they have both.

My previous cars have all been made in Japan and have had metric sized fasteners (bolt heads, etc.). One of the exceptions is the wheel lug nuts, which were all ¾ inch.

My current car is a Tesla, which is one of the most “American made” vehicles. All the fasteners are metric, including the wheel lug nuts, which are 21mm. All of the measurements in the service manual are metric, with imperial following in parentheses where appropriate. For example torque values are in newton-metres (Nm) with the equivalent imperial pounds-feet (lbs-ft) in parentheses.

Vehicle gas mileage is measured in litres per 100 kilometres and fuel is sold in litres and road speed limit signs are in kilometres per hour.

Through-hole DIP IC packages primarily have 0.1 inch pin spacing. It’s is also a common size for header pin spacing. Therefore, it’s the spacing used for solderless breadboards and perfboards.


Sure, me too, who doesn’t. I’m talking about the drive end of the ratchet, dimension (a) in this illustration.


Is there anything other than imperial dimensions for sockets? As far as I am aware it’s all 1/4, 3/4, 1/2 and 1 inch

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And as long as we are talking dimensions, the Arduboy is based off the credit card format, which seems to be designed in imperial numbers. I’m guessing the width is just an aggressive rounding of .3 repeating.