We all like to think that we have enough tools to go from the beginning to the end of a specific repair task. But sometimes we may not have quite the right tool. Decades back I needed a 9/32" deep well to undo interior fasteners on an old Ford. the parts stores were all closed and Sears too and all I had in my toolbox was a short 9/32". I dug around in my cheap socket box and found a stripped out 9mm. I promptly welded it to the 9/32" socket and now I had myself a deep well socket. It was a long time before I needed such an odd size again that it didn't get used for a while, however in more recent history when I spent a lot of time working on Fox body Mustangs it got used quite frequently. It turns out that 9/32" and 7mm are very close to the same size and now this old tool is used a lot. 7mm is also a popular fastener on Explorers.