It's only stupid Amerriccuns that don't understand metric. Wheeze smart'uns know how. I learned metric back in 1972 when my Mom purchased a 230 4 door Mercedes-Benz. Being 14 and having to fix the car daily, I had to learn metric, (and also found out that Mercedes reliability was a myth). Working in the Aerospace industry we go back and forth constantly. So us smartun's know both and interchange them routinely. (p.s. There's more hardware (nut and bolt sizes) in American standard than in Metric). I love them both, as I love metric women.