Join Date: Mar 2009
Location: Bucks County, PA
Give us a little more information. Is this a Phillips screw? Are you saying that the 'X' slots of the screw are torn out so the screwdriver won't grip? Is rust involved?
If so, Have you tried to drill the head off? Just use a drill bit a little bigger than the threaded portion of the screw and drill away. Once the head is off, remove the throat plate and take the remains of the screw out by turning it with a pliers.
Another solution might be to get under the saw to see if the threads are exposed on the other side so you could get it turning from that end.
Is the throat plate metal? If so, heat (a propane torch) might get things going. Don't burn down your shop!