Yes! We have no metric drill bits.

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.

12 thoughts on “Yes! We have no metric drill bits.

  1. I agree about the embargo we have against ourselves progressing into the present with the rest of the world. At my local Ace hardware, the associate said he “hates all things metric” when I asked for M6 fasteners. It would be fun to go into an “American” hardware store with a hidden camera and ask for 10 meters of rope, chain or wire. Edit for content and viola! instant comedy. (I know because I’ve done it before, just without the camera. It was like asking for the time from a dog.) You could probably turn it into a comedy / reality show. Be sure to get Billy Bob to help you. If the associate speaks with an accent though, they might just hand you 10 meters of product. (Once I went into a Subway sandwich shop and asked the East Indian guy behind the counter for a 30 cm meatball sandwich. He asked if I wanted that toasted.) So far, the best place to find metric only tools is ebay and amazon. I have several metric only tape measures (30 m, 8 m and 5 m), a 2 m folding ruler, meter sticks, a 5 piece step drill set, Celsius thermometers and a kg only bathroom scale among other things. You just have to get passed the fact they describe the items in inches and pounds.
    Wouldn’t that be 40 µm per side? 2,380 µm – 2,300 µm = 80 µm then /2 = 40 µm.

    • I hope you find someone to hold the camera and go for it!

    • I actually asked for ten metres of coax at my local Home Despot a few months ago– running an outdoor antenna.

      The clerk looked at me with the exact same expression as if I had just placed my entire order in Korean. I figured out the likely reason for the silent treatment and grudgingly asked for “thirty feet”. Yes, I could have been more exact, but the project itself had a lot of slop in it anyway.

      • I did that, too. Went to a electronics distributor and asked for 10 meters of coax for a project. I got 2 reactions from the staff. One went on a Donald Duck like tirade about “meters should only measure Volts, Amps Ohms and the like! Blah Blah Blah!!!” The other was willing to cut 10 meters of coax, but wasn’t sure how long that was and had to look up the conversion, do some math and all that. Their cable rolling/measuring machine only measured in feet of course.

        • When an employee does that, the best thing to do is get their name and report them to their superior. It is one thing to say they don’t carry some product, it is another thing to act in a child like mocking sense in the presence of someone paying their salary.

          If the store manager won’t give you satisfaction, go up the ladder until you find someone who will put an end to that nonsense.

      • Well then, they just lost a bit of business (30 ft is shorter than 10 m by almost 3 feet).
        Bring a meterstick (or a metric tape measure) next time.

        At least you weren’t trying to buy A4 paper at the office supply store next door!

        Bottom line: The American people are *emotionally* attached to their traditional weights and measures. It’s as though they (the weights and measures) are some kind of symbol of national identity, like the flag. That’s what you’re up against, Maven.

        Now it’s time for me to leave here and work on those calendars I told you about.

  2. I must be lucky as the down I live in has a McMaster-Carr warehouse and all of the metric parts we need are available from them. We do not buy from hardware stores, Home Depot or Loewes. I personally have not purchased anything from a hardware store in a decade or so. They never had anything I needed. How they stay in business is a mystery as they have few customers and they are over priced.

    Of course, everything as far as the company is purchased with a PO, no cash or cheques. 20 years ago metric parts were hard to get, but not now. The mentality of small business and start-ups need to change if they are to stay in business.

    They do have a 2.3 mm.

    Also try and pre-order. Do order just when you need it, order it ahead of time.

    I believe that 50 % was determined from a survey conducted of businesses a decade or so ago. I know I responded to a survey back in the ’90s asking if we used metric. Some companies may have answered they do for fear that if they say they don’t, they could lose some customers or potential customers who do use metric.

  3. Don’t blame them, please…Don’t blame those poor employees who are “Functional Illiterates” in learning, knowing, and applying metric units. Do you know who to blame? Simple answer: Our “excellent” POLITICIANS. Months ago, I delivered myself a petition letter to U.S. Representative Mr. Trey Radel in his Cape Coral Office, Florida, asking for support to my Metric System Project with all necessary documentation. This is the time I have not received any response from this politician or his legislative assistants. But, guess what? U.S. Representative Mr. Trey Radel PLEADED GUILTY ON COCAINE POSSESSION!!!!! COCAINE is still “ILLEGAL” in United States of America. However, the METRIC SYSTEM OF MEASUREMENTS or INTERNATIONAL SYSTEM OF UNITS (SI) is still “LEGAL” WHAT A CONTRADICTION!!! Neither Mr. Radel nor any of his legislative assistants have taken a little time to look at my Metric System Project, but, Mr. Radel had enough time to look into the COCAINE. This is just one of the worst jokes I ever had!

    • And we wonder why the US is in declined and being bypassed by countries like China and Germany. It is survival of the fittest.

  4. American’s have a mighty problem when it comes to individual rights versus the welfare of the whole. If they can’t manage the serious problem of gun control what hope has metrication got? All this talk about metric being the preferred system and everyone can use it is nothing but a sop and will stay so till America becomes irrelevant. I have said it often enough, metrication can never be introduced on a voluntarily basis and every politician knows that. No wonder they ignore it, not one of them want’s to be associated with, wait for it “COMPULSION”, never mind how advantaguous it is everyone. They remind me of their English/ Canadian counterparts, who never managed to go the whole stretch for exactly the same reason. They rather burden / handicap their youth so old fogies/voters, who think they can’t handle change are appeased. Intelligence and would you believe it compassion for their unnecessarily burdened/handicapped youth comes nowhere into the equation.

  5. … Where they, say, among other things, that also the famous Black & Decker metricated: but it’s not so clear if they did it for all products, or only for some; for example, here:

    … drill bits still seem to follow the old USC standards; not good, at all…

    Anyway, if the US is to metricate “from the bottom up”, people should be *much* more passionate about it: one can understand that most politicians don’t care, because often they want power rather than rationality and beaty; but ordinary people should definitely care, especially in the era of the worldwide web, where it is important to have a planetary measurement system, among other things.

    People already are accustomed to rational things, even in the US: for example, your telephone number format is among the best in the world: unified across North America (while this is still not the case in the EU, for example), and with a fixed number of digits (à la (x) xxx-xxx-xxxx); so, why not be equally and even more rational also on the measurement front, thus going fully metric?

    BTW, in science divulgation TV programs they should also use metric, not USC (as they often do now; which is unacceptable, to say the least, also considering that they are scientists): that would be a good place to begin with (and TV/web in general), in order to further facilitate reciprocal metric education in everyday life.

    Well, let’s hope that things will change for the better, anyway…

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