Super heavy duty cast steel handles for professional use Extra heavy duty cast head design is 20-Percent stronger than competitive brands Chrome Molybdenum hook and heel jaws for longest life and maximum grip Jaws hardened to HRC 52, 58 Powder-coated for maximum resistance to corrosion Induction hardened teeth provide exceptional grip Heel jaws attached using roll pins for easy replacement Meets US Federal Government Specification GGG-651 type II Class A