Made of high carbon steel with carbide grit edges to cut ceramic tile, marble, composites, masonry and slate. Hole saws have high carbon steel body or strength and durability. Includes 3/4in., 7/8in., 1 1/8in. and 2in. hole saws, 3/8in. and 1/4in. mandrels with pilot drills, and a hex key. Limited lifetime warranty.