Bi-Metal Hole Saw, Actual Hole Size 1-5/8" (41.3 mm). Bulk Pack of 50. Cut through steel, tin, aluminum, fiberglass, wood and plastic. Deep 1-5/8" (41.3 mm) cutting depth allows for cutting through 2" x 4" wood studs. Extra-tough bi-metal blade- we use the highest grade oftool steel to outlast compe