Right on. Metric is dead simple to work with, since much of the math is simply factors of 10.
The difficulty comes when faced with the large installed base of machinery & measuring equipment built in imperial. Many shops have older imperial equipment; than have a mixture of imperial & metric (a sure recipe for disaster), they’ll actually switch newer metric machines to imperial. On modern CNC machinery, this actually reduces the accuracy.
And it’s not just as simple as replacing all the dials, handwheels, and readouts to metric. Imperial machines are made with imperial parts; the ballscrew or leadscrew that handwheel turns is machined to be 0.1" per revolution; swapping the graduations on the dial to metric but leaving the 0.1"/rev leadscrew in place messes things up.
It’s not just all the old fogeys not wanting to switch. There’s a massive amount of machinery & tools to be replaced. Heck, I’ve been in shops where the main castings of a machine are from 1910. New ways, new motors, sometimes even a modern CNC controlling it, but the original iron is still good.
