The Invisible Metric Embargo

By The Metric Maven

Bulldog Edition

About four to five years ago I’d had it with imperial measures. I decided I was going to set my engineering lab up with nothing but metric. The first purchase I made was a dial caliper. I next wanted to purchase an honest to goodness meter stick, with only metric markings and not dual scale with inches. I went to the local metric supply store, and they were puzzled that I wanted a meter stick with nothing but  a metric scale.

Where could I get a meter stick? Well, our friends in the Great White North are metric—right? I trolled websites looking for high quality meter sticks. All I could find were painted wooden ones with centimeter markings. I purchased a pair and waited for them to arrive. It bothered me I could not find metal ones.

For six months to a year, I muddled through using small metal rulers with dual scales, all centimeter with millimeters between. I had converted my software and other computer aids to metric. It was then I first heard some of Pat Naughtin’s lectures, which were eye-opening for an American.

I fumed at the lack of metric availability in the US, and wrote an editorial which was published in a local paper. Pat Naughtin and Mike Joy, both from Australia, commented on how pleased they were I had spoken out. Mike contacted me by email and wanted to know if there was anything he could do to help. I told him I had one hell of a time finding metric only rulers in the US. Mike generously said he would send me some. I insisted I pay him, but he was more than pleased to send them along without prior payment.

When they arrived I had a 150 mm, 300 mm, and 600 mm set of beautiful steel metric only rulers. I was just dumbfounded. I’d never seen such things. They were easy to read, simple and elegant compared with imperial and the Canadian meter sticks. When I began using them I was in for a second revelation. All engineering drawings I’ve ever seen are in millimeters. When I was using my milling machine to create parts, suddenly it was much, much easier to read the measured dimensions of prototype PCBs. I pondered, and then realized I had been converting centimeters to millimeters in my head, because the Canadian meterstick was in centimeters. I had been doing an unconscious conversion without realizing it, constantly moving decimal points in my head.  Once I no longer did this, I noticed the ease of checking dimensions on machined PCBs, but it took me a while to realize why.   That was when it dawned on me that centimeters were indeed a bad idea.

Australian 300 mm Metal Ruler

Mike was very eager to help me obtain real metric-only tools from Australia. He also had an eye for quality tools. I was able to purchase a mm square, and a machinists combination square. To my surprise I was able to get a metric radius gauge, by mail order, here in the US.

The most interesting tool Mike was able to provide, was a true metric socket set. One of my complaints is that all the metric sockets in the US are just American sockets, kludged with metric ends. What I mean by this is the drives for various sockets are 1/4″ , 1/2″ and 3/4″ with metric on the other. My father has complained to me on numerous occasions about finding the right adapters to go between these different size drives. I was lectured several times by multiple people that Americans invented the socket wrench, and our drives were the international standards, so even if they gave the drives metric dimensions, they were actually in inches. I could almost hear a fife and snare drum in the background as they talked—like a speech given by Oliver Wendall Douglas..

When the metric socket set arrived from Australia I was was again dumbfounded. Once again my fellow Americans were talking out of their posterior. They just assumed what the rest of the world was all about. I had proof their viewpoint was so much intellectual vaporware. Below is a photograph of my metric socket set. It has a 19mm drive, with adapters for the old fashioned 1/4″ and 3/8″ imperial socket sets. A short 80 mm extension is included. It is a Tradesure Part No. TS4019.

Australian Metric Socket Set

It was at this point I began to realize, I lived in a country that has an informal, invisible, and strict metric embargo in place. The rest of the world enjoys the use of metric only tools, but they are never imported or sold in this country. If Mike Joy had not volunteered to help me break this metric embargo, I would have not been able to outfit my Engineering Lab  with all metric, millimeter based tools.

Mike made a trip to the US and stopped to pay me a visit. He brought a set of metric drill bits from Australia, and showed me a millimeter metric tape measure from Australia. Mike was willing to give up the drill bits, but he’d promised the metric only tape measure to another friend he was visiting. I wanted a millimeter only metric tape measure, and hoped Mike would send one once he was back home.

Unfortunately, incidents in Mike’s life prevented him from helping me further. I was now on my own, I had to do my best to break the invisible metric embargo. When I first began to purge my lab of imperial tools, I had purchased a metric-only tape measure, but it is “US designed” and has centimeters and millimeters. I was completely over using centimeters. I put the old centimeter tape measure in a beat-up old tool box, far away in the back of my garage, with my imperial tools. I looked and looked online. One American manufacturer had a millimeter based metric tape measure in their catalog, but when I called them, it was “discontinued.”

One day my luck changed, I found a boat-building supplier that had metric tape measures, they were all centimeters, except for a small one that was millimeter based. I was willing to take what I could get at this point. I purchased two. They were better than not having one at all. The boat building supplier then stopped offering metric tape measures. I wanted a larger, easier to read, mm tape measure. I found a supplier in Australia called Bolts & Industrial Supplies. I could get metric only tape measures from them I was told, but the shipping would be very expensive—and it was. I was also able to cross-reference Mike’s set of rulers and get extras, along with a true stainless steel, millimeter graduated, meter stick.

Tape measures in mm only — Good luck finding one in the US (click to enlarge)

I thought I was through purchasing tools for my lab, but I then realized why my metric calipers had been so hard to read. The dial was millimeters and the slide was centimeters. I had been converting the value on the slide from centimeters to millimeters, and then adding the millimeter reading from the dial. An American distributor had sold it to me. I finally located a millimeter based set of dial calipers, and the mixed set were banished.

Over and over I’m told, “hey, this is America, you can choose to do metric if you want, nobody’s stopping you.” That is a load of bull. There is no choice of quality metric tools in this country. But there is often a choice of inferior ones. I receive catalogs for machinist tools periodically, and they are all imperial sized. They offer endmills that are 1/4″ or 1/2″ or 3/8.”  No metric listed, no metric offered, no choice in America.

Millimeter Combination Square

Ninety five percent of the worlds population uses metric, and we try to put our hands over our ears, close our eyes, and ignore them. The absence of quality metric-only mm based tools in the US demonstrates this truth most effectively. It is proof of an invisible metric embargo. The lack of metric in our economy makes it far less competitive than it could be. The European Union has a larger economy than the United States. China is projected to have a larger economy than us by around 2016. A metric switchover would be a sound investment in our future, stimulate our economy, and make it more competitive. We could rebuild our bridges and infrastructure more cost efficiently in metric, and get more for our tax dollars. This would allow US workers to experience metric only building, which would in turn help us to competitively bid on metric building construction overseas. But I guess these are not priorities in Congress, or among the American public, but they should be.

Updated 2017-08-14

Related Essay:

The “Preferred” Measurement System of the US


If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is not of direct importance to metric education. It is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.

4 thoughts on “The Invisible Metric Embargo

  1. I’m an Australian living in Norway. Even in Norway, which is almost exclusively metric, they don’t seem to sell mm-only tape measures. When I moved here a few years ago and needed a tape measure, I was shocked to find that none of the local shops I checked seemed to have any alternative to the cm-based tape measures. While at least they didn’t bother with any inch measurements, after struggling with the same problem you describe, I ended up getting a proper mm-only tape measure when I visited Australia again.

  2. Hey there.
    EE here, from Brazil. Although pure mm measurements are rare in “general population”, they are pretty common, not to say the norm, on engineering works, studies and reference material.

    We usually have to fight the opposite fight here, when we need to import some piece of material and manage to convert the sizing to metric as to fit it.

    Same with screwdrivers, socket and usual wrenches, where usual measuments tend to contemplate the Imperial units. This is aggravated when trying to import not from the US, but also from China. Since the US is still the prime economy worldwide, most specs come in Inches or fractions thereof (which is not that surprising, since the datasheets and documentation, and heck, even this comment, is in English).

    Anyways, if you have the need for some quality metric instruments, drop me a line! I’ll see what I can do to help you. Also, if you’re looking for perfection, go for german supplies. In terms of engineering and standarization, they’re by far the best!

    Greeting!

  3. The problem with metric tools is one that I experienced today. I’m spending my vacation at the summer place and I had a table that needed some repair. To make it a bit more sturdy, I drill a hole in the side of the table with a 5 mm drill bit and screw my torx screw into place. All of this with an old Bosch power drill. But the table was rotten so the screw tore away most of the plank and I had to unscrew the screw. The problem was that my old Bosch had no reverse gear, so I had to unscrew the torx screw by hand with my bit screwdriver. But I couldn’t get enough torque with the screwdriver so I went to find a ratchet. And luckily I found an old one in the garage, excellent, now I only had to attach the torx bit to the ratchet with a converter bit.
    But no, that was not going to happen. The torx bit was 6.35 mm and all I had in my metric ratchet kit was 6 mm. Either you go all metric or you don’t go at all.

    You say that the rest of the world uses metric, but I still come across inches and feet everyday, and I live in Sweden, a supposedly metric country.

  4. I bought an 8m, mm ruled tape measure from eBay manufactured by Stanley a few years ago, but I couldn’t find a metric only version for sale anywhere else (even Stanley’s website doesn’t list it). The eBay seller must have gotten a bunch in bulk from somewhere overseas as they had many for sale. Unfortunately, I don’t see the same one for sale on eBay anymore. Anyway, here’s a picture of it: http://i.imgur.com/TYB8L.jpg

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