Features and Benefits: Use with Arbor 11122 or 11123 1/4″ Cutters fit 3/8″ and 1/2″ hand held drill chucks Includes 3 in a pack Made of M2 high speed steel This series cut holes 3 times faster and last 10 times longer than twist drills or hole saws for precision hole making in sheet metal and frame materials up to 1/2″ thick. Blair Rotabroach annular Cutters make clean burr-free round holes with no deforming of stock or damage to the surrounding material. There s no dead zone so less thrust is required and no deforming of stock or jagged edges occurs. Multiple cutting teeth precision ground which allows for a long tool life.