Heated discussions come up in the comments section every so often, where American tool users either complain about the glacial pace of adoption, or opine on how inches, pounds, and other such units are just fine.
30 years ago, I was taught as a kid that metric units would be the future standard in the USA. So… when’s that happening?
There are 1,000,000 mm in a km. How many inches in a mile? Um…
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A recipe calls for 3/4 cup of flour. You want to make half a batch. That’s… how many tablespoons? (Why are we still baking with volume anyway, weights are so much better!)
How many ounces are in 3.4 pounds? I need a calculator to tell me 3 lbs 6.4 oz.
Meanwhile, the range in temperature from 68°F to 72°F feels quite different. That’s 20°C to 22.2°C. I prefer the resolution of Fahrenheit.
Scientific fields use international standards, which are predominantly metric. There are some differences, such as with Kelvin being more common for temperature.
But in engineering, imperial units are still popular.
Things get messy when converting things like inches per minute to mm per second.
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What is the nominal size for a letter F drill bit? I know it’s the clearance size for 1/4″, but had to double check the actual size.
Oops, it looks like I was wrong. Apparently, according to Google’s AI Overview, an F drill bit, with 0.257″ diameter, is “commonly used as a clearance hole for a 5/16-18 fastener, allowing the bolt to pass through freely.”
0.257″ is a clearance hole size for 5/16″ fasteners?!
Here’s where inch units get in the way. What’s the decimal for that again? I always seem to remember for 3/8″ and 5/8″, but need a calculator for 5/16″. That’s 0.3125″.
How is a 0.3125″ fastener going to pass through a 0.257″ clearance hole?
My brain is firmly anchored in both worlds – I can’t process inch/SAE/imperial units for certain things (mainly science contexts), but I also can’t think in metric for a lot of engineering and construction-type contexts.
Orange juice isn’t sold in half gallon cartons anymore – Tropicana is down to 46 ounce bottles. How many quarts is that? There are areas where metric units such as liters and milliliters just make sense.
Bottles of water and other beverages are sold in liters (33.8 ounce). But then we have 12 ounce cans and 46 ounce bottles.
It is what it is, we deal with it. It’s like how Phillips head screws and screwdrivers are still around – because change would require impetus.
Money has been spent on getting rid of BPA-containing plastics in many consumer goods, and getting rid of paper straws and plastic bags in many areas around the country. Certain artificial food dyes are being phased out in the USA.
But deliberate efforts to simplify how you buy liter bottles of soda, orange juice in ounces, and dairy products (milk, cream, etc) in quarts? Nah.
Every now and then frustrations poke through in the comments section, because yes metric vs non-metric is messy.
So, here’s your chance to rant about the metric system in the USA – or lack thereof. I guess it’s an opportunity to rant about the state of “AI” too.
Bonus: “The Metric Continuum”
This chart, by Elizabeth Benham at NIST, explores the concept of a “metric continuum.” Their blog post also references the concept that becoming metric is not a one-time event but a process that happens over time.
The USA is moving there, albeit very slowly.
At what point do I want to adapt further? That’s a serious question I ask myself. As I plan out my next project, my inclination is to use imperial units – mainly inches. But is it worth forcing myself to think about things in metric dimensions, such as mm, and should I design from scratch using metric hardware, such as M6 instead of 1/4-20? “Maybe next time.”
EG
Metric is superior for sure, agreed on Fahrenheit, and AI sucks ass
Adabhael
This is the first and also winning comment. No more needs to be said.
Avi
Mainly agree, with one caveat for metric, fractional measuring is very handy for when you need to get a bit more accurate.
Wayne R.
I’d say just the opposite.
John
In doing CAD for my projects, I use standard and metric. Not that big of a deal. Digital calipers make that easy.
On to more pressing matters, AI is successful at only wasting large resources for garbage gain. Where are all the medical breakthroughs, or calculations that solve real financial issues. Oh yeah, nowhere. People are making stupid AI videos, or just too lazy to find real information instead of being spoon fed slop. The entire estimated U.S. GDP increase this year can be attributed to AI spending alone.
Ron
Until all us old time tradesmen are gone. Including me. We will continue to use imperial or inches. We grew up on it, it was pounded into us. It’s all we’ve ever used. The next generation can deal with Metrics.
Jason Watkins
I work for a car manufacturing plant. We deal entirely in MM. Most things have a tolerance of less then 3MM. 5MM is the highest tolerance I’ve ever seen. trying to use “American” measurements wouldn’t work at all.
Matt_T
The pro metric crowd push the slightly easier math benefit hard whilst ignoring the considerable real world costs of switching. And it’s really debatable whether the math advantage still matters in the computer age when the kids who’ll be taught metric aren’t taught math anymore.
Tony
Why is it such a bad thing to have both?
I think it’s more of a financial issue as to how much money it would cost for us to make the change — including making changes to software, signage, rewriting legal standards, etc. Who is going to pay the enormous price tag?
Avi
Even putting money aside, people tend to develop a feel for approximating measurements with the units they use, similar to immigrants and languages. Not sure all those raised in imperial are willing to emigrate to metric living, however after a generation or 2, everyone should be fine
Wayne R.
Someone a long time ago told me that, “kilometers and megahertz were pretty much the same.” And we were in roles where that was pretty important.
And for conversions, just look at Amazon with lots of vendors trying to sell the same thing, the sizes, weights, counts and “cost per” units vary wildly to the point of near uselessness.
I generally prefer metric, but temps are difficult – especially mental conversions in between the two zeros (for me, anyway).
I’m sure we still have Imperial/customary/SAE/silly mishmash because most people just dislike thinking.
Matt
Lol, and I did the imperial wrong in my head, I should type slower.
51 and 7/8 divided by 2 is 25 1/2 + 7/16 = 25 15/16 (=0.938)