The LENOX® Tools Bi-Metal Speed Slot Arbored Hole Saw with T3, 3-1/8"-79mm, has enhanced tooth geometry that cuts 50% faster than previous LENOX® hole saws. Twice as durable as our previous generation when cutting through metal, this bi-metal hole saw with a standard arbor features thicker walls to minimize tooth loss and improve durability. A staircase SPEED SLOT has a wide slot placed low on the hole saw and multiple leverage points to make it easy to work plugs out with a screwdriver. This design effectively removes sawdust and chips and helps prevent plugs from becoming stuck in the saw. 10% taller than previous models, it delivers cleaner cuts through two-by lumber.