Bi-Metal Hole Saw, 3-1/2″FeaturesRigid solid steel back plateDiamond sides provide quick plug removal (available on 7/8 in. to 6 in. hole saws)4/6 variable pitch geometry with unique fleem ground teeth designCats eye openings on solid back plate(available in 2 in. to 6 in. hole saws)Featuring a 1-7/8 in. depth of cutConstructed from M42 high speed steel with 8% premium cobalt content