Category Archives: Metric Reform

A Kilotonne is How Much in Metric?

Posted on by

By The Metric Maven

Bulldog Edition

When I was in college, I studied Electrical Engineering. I was told many times that one was no longer to use concatenations of metric prefixes, this was considered very bad practice. What this meant was that one should not use two metric prefixes concurrently to designate values. At that time there were capacitors which were marked micro-micro Farad (μμF). Micro is 10-6 so two of them together would 10-6 *10-6 or 10-12. There is a perfectly good metric prefix called pico to describe this small amount of capacitance. The slang term is puff. So these μμF capacitors should be described as picofarad pF capacitors. This made perfect sense to me. I was surprised that such an ad hoc nomenclature would make it into engineering or be tolerated. When I took my first job, we used a device called a directional coupler to calibrate the power level of measurements. The coupling factor for the directional coupler was shown on a graph which was on an attached metal plate. The coupling was different at different frequencies and the graph was used for correction. The frequency axis of the graph said KiloMegaCycles. I knew this designation was from a long time back as cycles per second had been called Hertz for decades. I found this antique item to be a source of humor for me.  Who on earth would write a frequency in Gigahertz (GHz) [109] as (KMHz) [103 *106 = 109]. How on earth did that make sense? What I didn’t realize was that the US “do your own thing” anarchy of weights and measures allows, and seemingly promotes this type of designation.

Imperial and US Olde English unit usage have been retained in the metric system, and have never been purged as they should have been. I’ve spent considerable time expressing my views about the centimeter as a pseudo-inch, (and have condemned the entire prefix cluster around unity), but there is a much more sinister and in-your-face Imperial/US Olde English holdout in the metric system. It is the tonne. The fact that there is an extra n and e should make one think Ye Olde English metric. The designation tonne is actually an approved usage!  The tonne is properly called the Megagram or 1,000,000 grams, but when used in a completely feral manner they are known as metric tons—no extra n or e, just pigfish. So what is a metric ton? Well it’s 1000 kilograms, or 1 kilokilogram (KKg). It turns out that 1 kilokilogram is close to a short ton (0.907 kilokilograms). A ton is probably derived from a tun which was the weight of a barrel of wine. So why was it so important to taint the metric system with an unnecessary non-metric-metric unit? Had someone been drinking? Worse yet the metric ton is just another way of writing kilokilogram and pretending it isn’t poor usage. If I wrote something has a mass of 97 kilokilograms I’ll bet most pro-metric people would wrinkle their nose and pitch a small fit, but If I said 97 tonnes or even 97 metric tons, well, only the tinkling of ice in glasses around the metric table would be audible. How about K2g for metric ton?—I’ll bet that wouldn’t go over well either. So why is tonne or metric ton acceptable in polite company?

This blog was originally to be about Naughtin’s Laws and the press. I was curious about how “professional”  people talk about large quantities. Well, it turns out that there are many varied and mangled ways that this is done by journalistic denizens of the only country which embraces US Olde English Units. I was curious about the amount of metals produced world-wide, and found a slide presentation with this table:

When my mind encountered the word kilotonnes, it seized up for a moment and I experienced metric vertigo. Kilotonnes!!!  So in other words the amount of metal is being described is in terms of kilokilokilograms or KKKg! That sounds rather ominous—perhaps K3g would be better? Let’s see what would that be in non-pig-Latin metric? Oh, it would be simply Gigagrams. This is not to be confused with Gt which is proper pig-Latin metric for Gigatonne or in improper pig-Latin metric is K5g . The source of this table will remain anonymous. There is no need to single out this person, he never chose to be in the spotlight. But news items which are written by “Journalists” for the public, well, I’m less inclined to invoke a Metric Maven Client privilege. Lest you think this usage is uncommon, the article Great Balls of Fire in New Scientist on 2013-06-29 (page 42) describes the explosive impact of meteors in megatonnes and kilotonnes.  Here are some values in terms of metric tons I randomly found on the web using a google search:

  • Mining operations in Amapa, where Anglo American produced 6.1 million metric tons of iron ore in 2012
  • According to Philips estimates, using the LED replacement could also eliminate 11 million metric tons of carbon emissions annually, or the equivalent of removing over 2 million cars from the road.
  • This clean solar generation plant will displace the equivalent of approximately 54,000 metric tons of carbon dioxide (CO2) per year, which is equal to the amount that roughly 2.2 million trees would displace annually
  • “The ground fish fleet is a huge contributor to local port economies,” he said. “In my district alone, on any given year, you will have a dozen trawlers that contribute 10,000 metric tons of fish and that represents about $20 million worth of product,” he said.
  • The Wikipedia article referenced below indicates that the Earth has around 40,000 Gt of carbon in the hydrosphere, biosphere and atmosphere
  • More than 2,000 farmers in six communities in the Northern Region will benefit from a 500 metric ton certified warehouse for grain storage at Datoyili, in Tamale.
  • From July-February 2012-13 about 5,590,775 metric tons of cement worth US$ 376.85 million exported as compared to 5,589,372 metric tons valuing US$ 303.71 million of corresponding period of last year.

Do you really have any idea of the comparative magnitudes offered in these news stories? I would bet not. Let’s try to get a handle on these values using Naughtin’s Laws (mostly) and Metric Prefixes.

Material

Article Value

Metric Value

Iron Ore

6.1 million metric tons

6.1 Teragrams (1012)

Carbon

11.0 million metric tons

11.0 Teragrams (1012)

Carbon

54,000 metric tons

54.0 Gigagrams (109)

Fish

10,000 metric tons

10.0 Gigagrams (109)

Total Carbon  (Eco System)

40,000 Gigatonnes

40.0 Exagrams (1018)

Grain Storage

500 Metric tons

500 Megagrams (106)

Cement

5,589,372 Metric tons

5.6 Teragrams (1012)

There is no excuse for Americans not to have an idea of the relative magnitudes of Mega, Giga and Tera. Computer disk drives were in Megabytes, then as they became larger they came in Gigabytes, and now one can buy external hard drives of 1-2 Terabytes without a problem. Peta–well, that’s way big, but one can look it up online without a problem if needed.

The presentation of quantities using metric tons only obfuscates a person’s ability to immediately compare them. It also in many cases can serve to obscure the decimal nature of metric values and money. For instance here is the pricing of copper in one article:

  • Benchmark copper on the London Metal Exchange (LME) hit a session low of $7,439 a metric ton (1.1023 tons), its weakest since August 21, and closed at $7,465 a metric ton…

We note that the price is given in metric tons, and then they provide a conversion factor for US Olde English short tons. Let’s see, copper costs $7,439 per metric ton; how could we possibly compute the price of other quantities?  I have an idea, perhaps actually using the metric system might help?  How about $7,439 per/megagram, or $7.43 per kilogram, or 74 cents per gram. Look ma!—no calculator! The metric ton designation really screws up the simplicity of decimals, which is one of the reasons metric was adopted internationally in the first place. Seriously, the metric ton is just a tonne of problems, it should have never been accepted as a legitimate usage in the metric system. It only serves to obscure, and that means that for unscrupulous persons, it’s used for dishonest purposes. It’s not a metric ton, it’s a Megagram! Members of the press—learn to count!—by using the metric system!

Correction 2013-12-20 Total carbon corrected to Exagrams.

Related essay:

The Olde English Prefix Modifiers

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.

Yes! We have no metric drill bits.

Posted on by

By The Metric Maven

My Engineering career started with a number of years working in aerospace. This was where I learned that outside of the interior of a  computer program, metric units are unwelcome. Early on, I tried to argue against this, but the entire system is structured to maintain the use of decimal barleycorn inches and a feral unit called “the mil.” I was worn down after a prolonged period, and accepted the situation.  Following the disappearance of The Berlin Wall, I began working for a large consumer electronics manufacturer. There I was able to  use metric measures with very little push-back. I was later told that they had been using inches for years, but after they were purchased by a French company, the French were horrified and mandated metric. I’m sure the company would have continued its merry way with Ye Olde English if the new owners had not stopped the practice.

I had thus far worked for large companies, but then I found myself with an opportunity to work for a small start-up with about 10 employees or so. It was heady, intense and rewarding. One had to contribute in ways that were unthinkable in a large organization. The most notable difference was that this small company used Ye Old English fasteners and dimensions. I wasn’t happy about that fact, but I had been ground down for so many years that I lived with it. The start-up was purchased by a medium sized company which had a policy that one could use metric, but had to maintain it throughout the design. I was elated. I immediately switched over to mm. What I didn’t realize at the time, was that I really wasn’t using metric, but pigfish-metric. Everything else, pressure tests, pull tests, temperature tests, fasteners and so on were all Olde English. In reality I was only using millimeters, and not The Metric System (i.e. SI). Looking back I feel I was unknowingly put in the position of the accountant in a Monty Python sketch who wanted to be a lion tamer, and when asked what his qualifications were indicated he had purchased a lion tamer’s hat. This is the strange cognitive dissonance of measurement which is thrust upon technical workers in the US.

When we needed parts, we went to the local hardware store and purchased them. We did what we could to save time, and waiting for a large technical supplier to ship us parts, was only utilized when there was no other option. The default was to purchase Ye Olde English fasteners and such at a hardware store–because they were available.

When the avalanche of off shoring whisked me into unemployment, I managed to begin making a living as a Consulting Engineer. I vowed that I would uncompromisingly use metric, and only metric, when doing my designs. This insistence has caused a number of serious and humorous encounters with my clients over the years. I also did the one thing which US engineers seem to find unnecessary–I sought out advice, and found it in the form of Pat Naughtin and his work. I’ve been very pleased with the changes I’ve made with his guidance.

Recently, a client was interested in a design which is (thankfully) all in metric. I had  designed a printed circuit board (PCB) which was to be “heat staked” into a plastic piece. I also had the plastic 3D printed prototype in my possession to which the PCB would be attached. My prototype PCB needed to have its pilot holes drilled to a larger diameter, so they would fit the heat stakes. Because the PCB I designed is an electromagnetic device, the tolerance has to be tight. For the given heat stake diameter, I needed a 2.3 mm diameter drill bit. There was just one problem. I had purchased an inexpensive set of metric drill bits long ago with 2.0 and 2.5 mm bits, but I needed a 2.3 mm. Larger more expensive sets of drill bits do include 2.3 mm, but I had not spent the money. I looked online and indeed I could order a single 2.3 mm bit, but it would be a small cost for the bit, and a large cost for shipping, if I wanted it next day or by two day. I thought, well, it’s a long shot, but perhaps my hardware store has a 2.3 mm. It’s a bit uncommon, but I could luck-out.

I went to a nearby ACE  Hardware store. A fellow asked what I needed. I told him drill bits. We were right near them and walked up to a large wall of drill bits.

“It’s a bit uncommon, but do you have a 2.3 mm drill bit?” I inquired.

The fellow’s countenance became one of slight contemplation. Then he said “I’m sorry we don’t carry any metric drill bits, we only have standard.”

“No” I replied, “the label of standard is a misnomer. Ninety-five percent of the world’s population do not use fractional Olde English drill bits.”

“Well, that’s all we have.”

I then found myself searching through my tool box in exile which has Ye Olde English fractional drill bits. Inside the drill index I saw that the 3/32″ drill bit  had a number below it indicating it’s 2.38 mm. It uses a comma decimal delimiter 2,38 mm apparently so Americans would be sure to know it’s furin’ and not consistent with America, mom, and apple pie.  I pondered and pondered if 400 µm  40 µm extra per side would matter. I finally decided after a small amount of analysis to try it, and it did work.

“From My ‘Standard’ Set of Drill Bits”

When I later related this story to Sven, I suddenly realized that yet again I had accepted something singular as “normal.” No metric drill bits? They sell metric machine screws, but not metric nylon machine screws (I use these a lot in my work). What this implied to me was that if you have  something which is already metric, then we have some parts, but if you want to build in metric, this is not the place. As small businesses and start-ups are generally dependent on local hardware stores for quick turnaround on prototypes, this produces a bias toward Ye Olde English tools, fasteners and such. Should a business grow to the point where it has international dealings, it will be using “standard” parts, which are completely incompatible with the rest of the world. This is baked into the US cake because we’ve never had a government led metric switchover like Australia. We just have a government which enforces the use of Ye Olde English units.

Was this situation singular, or is finding a metric drill bit as difficult as finding an engineer who still uses a slide rule? I decided to do a bit of field work. Here is a short list of what I found:

Ace Hardware — No Metric Drill Bits “We only carry standard”

Harbor Freight — No Metric Drill Bits

Home Depot — No Metric Drill Bits “I don’t know why that is.”

Lowes — No Metric Drill Bits “We don’t carry them and I don’t think anyone else does either.”

Sears — No Metric Drill Bits  MM: “Do you have any metric drill bits?” Sears Assistant: “No Sir, they are all SAE.”

The woman who helped me at Lowes mentioned that they had a few metric screws, but not much else. Others had come into the store and commented they had more metric fasteners than anyone else, and they don’t have much. I’ve not found a hardware store that sells metric nylon machine screws, and when I asked, she indicated they didn’t have any.

The fellow who works at Sears indicated that the bits were all SAE. Well SAE stands for Society of Automobile Engineers, and I’m fairly sure that except for a few parts which help to camouflage the fact that Automobiles are all designed in metric, makes this statement almost nonsensical—except in the US.

My informal sampling of local hardware stores confirms a point which I’ve made in the past. There is an invisible metric embargo in the US. It also shows that Dr. Gallagher’s assertion that we can use metric if we want to, demonstrates that he doesn’t get out of the NIST building much. It is possible to obtain metric drill bits and some metric tools from industrial houses such as McMaster Carr or MSC, but this must be done by post, and one cannot go down to a local store.  Other metric tools, such as mm only rulers, tape measures, squares and so on are simply not available, even at these industrial suppliers. The answer at all the hardware stores was Yes! We have no metric drill bits.

We’ve been hearing from metric advocates, for many number of years, that the US is 50% metric. What this actually means is not clear or well defined. This brings me to my final point, that the assertion which claims the US is 50% metric appears to be unfounded and a non-statistic. It has been pulled from the thin air of wishful thinking. Small start-ups use what is readily obtainable, and anything that takes time to obtain, is neglected, unless there is simply no other option. People will not go on a “metric snipe hunt” just to possibly obtain metric fasteners, tools, metals, sandpaper and other items used in the fabrication of a product. It’s time we faced up to just how large the problem is in the US,  and quit waiting for some imaginary “Darwinian pressure” to bring metric to the US. We have been waiting for 150 years. Continuing to wait for metric tools to appear in US hardware stores of their own volition  is a fool’s errand, and we in the US look more and more foolish every day.

Related essays:

Without Metric Threads We’re Screwed

A Hole in The Screw Head

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.