A Question of Convenience

Irish-Corned-BeefBy The Metric Maven

Bulldog Edition

My favorite meat market is supervised by a long-time Irish immigrant to the US. He is of good humor and was pleasantly surprised when he realized why I came in and generally ordered 0.45 pounds of hamburger. “It’s 200 grams” I pointed out one day. Like most persons who have lived in countries with the metric system he immediately exclaimed “The weights and measures here are crazy, I don’t understand why they do it. It took me a long time to get used to them.”

He noted that people can be very exacting about their measures. One day a patron asked for a steak cut to one-quarter of an inch. When it was placed on the scale, the Irishman asked if that was good. The customer reached into his pocket, produced a tape measure, measured the steak’s thickness and indicated it was close enough. The Irishman was floored by this.

During the Winter, I generally carry a millimeter-only tape measure with me. I produced it and told him that from now on I was going to demand my steaks be to the millimeter. The Irishman assumed it was an inch measure, so I pointed out that it wasn’t. He was so surprised he came around to the customer side of the meat counter to get a better look at it. We commiserated about the lack of the metric system in the US. Now and then when I would come in I would pull out the tape measure and say “I need steak—to the millimeter.”

The market has been around since the 1940s and is still a “small-town” feeling independently owned family business. The people behind the counter recognize me when I do business there. One day I was asked “You’re the metric guy—right?” I admitted I am. He asked: “If we switched over to metric, how would we do business? how would we measure things?” I told him that only grams would be used mostly, and pointed to my blog showing how the UK packages its foodstuffs. “You would think of 1000 grams as a Kilogram or 2500 grams as 2.5 Kilograms with very little thought.” The values you would use would generally be all integers without a need for decimal points. He seemed interested. Liquids would all be measured in milliliters and would also be integer values without decimal points. You would sell 300 mL of barbecue sauce, or 250 mL of mustard, it would all be simple numbers. The person behind the counter was still not convinced. I jokingly said I would report his intransigence to the Irishman.

As I was driving back to my residence with my 200 grams of ground beef, I wondered what the best value for pre-packaging might be. When one goes into an ordinary chain grocery store in the US (not my meat market) the beef is generally found in one-pound packages. They are not really 1 LB, they are 1.15, 1.2, 1.1 and so on. Now and then you will find some that are 1.00, but it’s not a requirement obviously. It struck me that the constant argument for Ye Olde English measures is how convenient they are, despite their obvious awkwardness as in the case of pounds and ounces. If you buy one pound of hamburger you can make it two 0.5 LB patties, or three 0.333 pound patties or four 0.25 LB patties. One of the weird arguments made about the meter is that you have to have 0.333 meters when it is divided in three and so without a metric foot the metric system is somehow incomplete and irrational. If the embracers of medieval measures believe this is a valid argument for length, they should also consider it a problem for weight (mass) in Ye Olde English.

It struck me that pre-packaged ground beef could be sold in 600 gram packages. This would make it easy to have two 300 gram patties, or three 200 gram patties, or four 150 gram patties, or five 120 gram patties, or six 100 gram patties. Seven doesn’t work, but you see the point. This is similar to the choice of 600 mm center to center separation in millimeter only metric construction. It makes the simple arithmetic easy and generally works out to whole numbers. Of course this would also be true for 600 mL volumes, should one be interested in dividing them up in the most utilitarian way possible. When I had custom mm only metric rules fabricated to give to my best clients I chose 600 mm. It seemed long enough to measure a large number of everyday engineering objects, and also was a number which is easily divisible with a large number of integers.


The Metric Maven has published a new book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.

Soft (In The Head) Metric

But No Metric is so softBy The Metric Maven

Not long ago I was in an engineering meeting, and the persons involved were using inches. I attempted to convince them to use metric instead. The design was then quoted using a strangely odd number. With millimeters, the dimensions should now be round integers for the mounting plate and other design options. I protested that the design did not appear metric even though the dimensions were dual. The engineer looked back at me and said, yes it’s metric, we use soft metric here. I’m sure my jaw became slack when I realized what he was saying. I replied “soft metric is no metric at all.” After considerable discussion, I realized that I was yet again going to lose when it came to using actual metric in a US engineering environment.

One of the first times I encountered the idea of soft metric was in the monograph Metric Implementation in U.S. Construction by Andrew J. Holland. This report was written for Holland’s Master’s Degree in 1997. Here is how it defines hard and soft metric:

Hard-and-Soft-MetricOptimistically Holland states that only a few products will need to be resized for hard metric:

A handful of products which are considered to be modular products, such as suspended ceiling grids, drywall, plywood and rigid insulation, raised access flooring, brick, and concrete block fall in the category of “hard-metric” and therefore will need their dimensions changed to the new rounded metric numbers.

…and that 95% of products will not need to be altered. While this sounds promising, those affected in the US will ask for “exemptions”  which will become permanent, and then nothing will change. Take NASA for example, the rocket scientists there have been issued metric exemptions for decades. Any drawings they would ever generate in a “metric switch-over” would probably have both metric and Ye Olde English,  would continue to be drawn in Olde English inches, and after a time no one would see why metric is a superior idea, and go back to inches, like the California DOT did. Here is the US escape clause for construction:

Exemption-ExcuseThe idea is to change all of the important (modular) stuff to metric so the numbers will all be simple ones:

Conversion-1Unfortunately, we must be “flexible,” so there are exemptions for sheet metal thicknesses and such:

Soft-GaugeThe term gauge is meaningless and a fountain of confusion. Gauge values need to be given priority for reform. I have written about this problem in my essay Don’t Get Engaged With Gauge.

This type of metric change might possibly work in the building construction industry, if a mandatory metric-only metrication (no dual units) was implemented and most soft metric eschewed. In practice it has been crushed by the building industry. The idea of soft metric has been exported to other engineering disciplines in the US by those who want to maintain the status quo. That is what I’ve experienced in industry. Soft metric was waved in front of me as a distraction so Ye Olde English could continue to be used as soon as I left the room—and so that no metric changes would despoil our perfect engineering life in the US. The drawings might continue to have metric dimensions on them side-by-side with Ye Olde English, but the metric values would be ignored for the familiarity of the inch versions as Naughtin’s first law predicts.

Soft metric is pretend metric.


The Metric Maven has published a new book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.