Ordinary teeth deliver either speed or durability. NAIL GUARD ™ solves this trade-off with an aggressive 5 TPI pattern for faster cuts and a unique design that protects against tooth fracture.FANG TIP ™.NAIL GUARD ™.Ordinary tips bounce or skate on the work piece. FANG TIP ™ bites into the wood on first contact.Matrix II bi-metal teeth for greater durability.