I have a machine screw from the hardware on an old desk that needs to be replaced (the knob it goes with is slightly stripped so it needs a longer screw to catch when mounted), but it's a really weird size. The outer thread diameter is 3.7mm, and there are somewhere between 30 and 32 threads per inch (it's 1" long but last mm or so of the shaft is missing threads). This doesn't match any standard metric or US size (it's between #6 and #8 and as far as I'm aware there's no #7).
Best Answer
The closest thing I found to a match looking up various thread sizes with a 0.1875 inch British standard cycle, but even if that is what it is then I suspect you will find it extremely difficult to actually buy.