LESCALLOY NITRALLOY 135 MODIFIED VAC-ARC steel is a low alloy nitriding grade designed to provide a high case hardness and to maintain its core strength during the nitriding cycle. It has moderate hardenability. This datasheet provides information on composition, hardness, and tensile properties. It also includes information on forming and heat treating. Filing Code: SA-442. Producer or source: Latrobe Steel Company.