The WeldTec™ platform combines various attributes to deliver long lasting cutting performance. A revolutionary tooth geometry and an updated tooth set enables faster and smoother cuts, as well as improved longevity. IRWIN® Bi-Metal Hole Saws cut through a variety of materials, including: Aluminum, Copper, Iron, Stainless Steel, Wood and Zinc. The electron beam welded High Speed Steel (HSS) cutting edge ensures stronger, longer lasting teeth. Precision set teeth provide faster penetration and cutting. And, the bi-metal construction delivers toughness and long life.