Metric Thinking

I have been selling some metric tools (Proxxon) and actually using them too. I have discovered it is actually quite easy to work in either metric or SAE (inch) standards. There is no evil in either. I (almost) hate to admit I enjoy metric.

Of course the U.S. general prejudice to metric stemmed from our indoctrination, from what I now view in retrospect, to be a very lame educational system of the time. Post WWII there was a push for the USA to go metric. The requirement was to teach young children to exactly convert through (then) seemingly complex formula from one system to another. Remember, there were no calculators in those day. I could derive the equivalent answer but it made no sense why we would want to do this. The same thinking was crammed into our brains about temperature conversion.

In those days a student was not permitted to question the process but only to do as instructed.

As in learning a new language, it is very cumbersome to convert every word from one language to another. You only become efficient when you start thinking in the other language without the conversion. That is how metric should be understood.

I learned Morse code as a radio amateur. All radio operators will tell you that you do not become proficient until you stop counting dots and dashes and start “hearing” the sounds of letters. The really good can hear words. The very best hear Morse as a conversation.

When using metric hand tools I do not think of what millimeter is equal to in inch measurement. A good mechanic looks at a bolt and can say it is ½ inch or 12 mm, not stopping to think they are almost the same. When cars started using a lot of metric bolts, I had to buy a new set of tools. But I didn’t waste time trying to convert between systems. I can eyeball and think in metric hand tools as easy as SAE.

In today’s machine shop we can have smart tools. The new DroPro DRO I installed on my X3 mill turns the machine instantly between a metric and an SAE scale. I have an electronic caliper at a push of a button does the same thing. I have one lathe that is SAE and another that is Metric.

A cheap calculator or lookup table lets me almost instantly convert when I have to. Otherwise I just make measurements with the proper scale and “think” in that language. Why not?