Carbide Holcutters cut smooth, fast burr-free holes in all types of materials, from soft aluminum to tough-to-cut stainless and cast iron. Rugged construction for day in and day out use. All sizes have a "shoulder" to prevent plunge-thru, which is especially useful when drilling into live electrical boxes. Carbide tips provides long tool life and smooth cutting action. Carbide holcutters dramatically outlast bi-metal holes saws and step drills. All cutters include pilot, spring, and arbor. For materials up to 1/8" (3.2mm) thick.