This simple tool solves the problem of removing small or hardened screws broken off in wood. When you can't drill into the screw and use a conventional screw extractor, use one of these hollow bits to cut free a core of wood around the screw. Then pop out the core along with the broken screw and fill the hole with a dowel or plug. Use a plug cutter or tenon cutter (sold separately) to make invisible repairs using the same species of wood. 3/8" outside diameter extractor works for screws up to size #14.
Since this tool has no center point, it is best used with a drill press or guide block. To make a simple guide block, simply drill a hole the outside diameter of the hollow screw extractor in a hardwood block. Clamp the guide block in place and drill through the hole.