Bi-Metal Hole Saw Sets: feature positive rake, 4/6 variable tooth saws that offer more efficient chip clearan ce with less heat build-up than conventional hole saws. This produces smoother, cleaner cuts with less vibration, resulting in reduceed feed pressure and easier cutting. These saws have a full 1 1/2" cutting depth. Electricians Kit has a 1-3/4" cutting depth. The High Speed Teeth will cut everything from, aluminum, brass, copper, cast iron, and stainless steel to wood and plastic. Cuts easily through nails and screws. Bi-Metal saws can be used in air and electric drills, boring mills, drill presses, lathes, portable and magnetic drills.