With teeth that cut 50% faster than previous generation Lenox hole saws, the new Lenox Bi-Metal Hole Saws with T3 technology last twice as long even when cutting through metal for unbeatable performance and unmatched efficiency. These hole saws feature the innovative Speed Slot design to make plug ejection fast and easy. Lenox Bi-Metal T3 Hole Saws are ideal for work in both Ferrous and Non-Ferrous Metals, Wood and Nail-Embedded Wood, Drywall, Plaster, Plastics and Composites.