Dale: ... > the first bag of screws I ordered didn't have any size info ...
To figure out which thread one have, one usually use: https://en.wikipedia.org/wiki/Calipers to get the diameter. Given the diameter, and possible the table of thread sizes, one can sufficiently well infer which thread it is. You can use a thread gauge if unsure: https://en.wikipedia.org/wiki/Thread_gauge Regards, /Karl Hammar
