Bill, slightly off/on subject, talking inch and metric threads, on this island we tend to swop about from one to the other without much thought but this is not the case in mainland Europe. We used to have to redesign US machinery to use metric threads and bearings for machinery we built and shipped to Europe or we couldn't expect maintenance to be carried out properly because their spanners wouldn't fit and replacement inch bearings weren't available down the road. If we didn't redesign for metric they'd go to our competitors. My spanners and sockets are all colour coded so I know which type I'm looking for or life could get stressful!
Alan