Last year I was doing some painting with a paint roller. The arm of the roller broke and we were stuck with a half-painted wall on a Sunday afternoon (all the hardware stores were closed).
It occurred to me to see if the broom handle, which screws into the broom head, would also fit into the paint roller.
Perfect fit. I don’t know if this is an actually official standard of some kind, or it if was just done to save manufacturing costs for Handle Co. Either way, it saved the day.
There is a lesson here.