CARPENTER BARTO is a cold-melt, grain-controlled, electric-furnace chromium-nickel tool steel. It was developed for applications requiring extreme toughness. Barto's extreme toughness is developed at the expense of some wear resistance; however, it will harden to Rockwell C 55/56. Typical applications are clutch parts and expander punches. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-444. Producer or source: Carpenter.