I worked in oilfield and petrochemical construction and manufacturing for almost ten years, and I can say that we almost never used metric. I think in the ten

I worked in oilfield and petrochemical construction and manufacturing for almost ten years, and I can say that we almost never used metric. I think in the ten years, I worked on two projects that required metric bolts and fittings, both of which were for Japanese companies. Retraining the workers to use metric for these projects was a battle in itself. We built structures and equipment that went around the world... all using imperial.