ELASTUF PENN Machinery Steel is a special analysis 0.45% carbon steel that combines the most desirable characteristics of AISI C1045 and C1141. It might be accurately defined as an inexpensive, modified AISI C1144 because of its strength, machinability and excellent response to heat treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: CS-27. Producer or source: Brown-Wales Company.