For cutting holes up to 3/16" thick in a variety of steels, aluminum and non-ferrous metals. Engineered specially for Engineers, professional Electricians, Plumbers and Mechanics. Available from 9/16" to 5" in diameter. Features "triple-edge" teeth and an ejector spring for fast cutting and slug ejection. Unique design: Cutter, Arbor and Ejector Spring are manufactured as a single piece.