1144 steel, also called "stressproof", is an alloy that has excellent strength and hardness, and is specifically treated to relieve stresses in the metal created during the manufacturing process. This means that the bar is less prone to warping after it is machined or heat treated. Further, 1144 is easily machined. Typically used in nuts, bolts, arbors, gears, pinions, piston rods, sleeves, shafts, and screws. "Stressproof" is a trademark of the LaSalle Steel Co.