Product details:

Carbide Holcutters by Hougen cut smooth, fast burr-free holes in all types of materials from soft aluminum to stainless and cast iron. 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 inch (3.2mm) thick.