UP TO 50X LIFE *vs LENOX Bi-Metal Hole Saws cutting cast iron; High performance carbides are welded to the cutting edge for durability and to help prevent tooth loss EXTREMELY VERSATILE; Aggressive tooth design drills through wood, steel, stainless, cast iron, fiber cement & plaster FAST, EASY PLUG REMOVAL; Patented SPEED SLOT staircase design has multiple leverage points for easy plug ejection DRILLS THROUGH THICK MATERIALS IN ONE PASS; Tall body easily drills through 2x dimensional lumber for rough-in work