I recently noticed one of the screws holding my foot pedal down had gotten to the point where the threads weren't holding it down anymore. My first thought was to just find a slightly larger screw. Well, the head on the screw that worked didnt' fit down into the recessed base.
So I found these: some folks call them Well Nuts, or expansion nuts. They work great. I did have to widen the hole a bit with a 1/4" bit, but the expansion nut pressed in and holds great.