LENOX® Speed Slot® Hole Saw with T3 Technology, 3-1/2 in Dia Saw, 2L, 3L, 6L or 7L Arbor Hole, 1-1/2 in D Cutting, 95 rev/min Mild Steel, 45 rev/min Tool/Stainless Steel, 65 rev/min Cast Iron, 130 rev/min Brass, 145 rev/min Aluminum Speed, Bi-Metal Tooth, Applicable Materials: Mild Steel, Stainless Steel, Cast Iron, Brass, Aluminum