Lukens cold-work tool steels A2, D2, O1, S5, and S7 are used in applications where an air-hardening, oil-hardening, or shock-resisting tool steel is required. These steels are available in full-size, annealed plates suitable for saw cutting and/or finishing. Parts can subsequently be machined and heat treated to a range of hardness requirements. For improved internal cleanliness, all Lukens cold-work tool steels are produced with maximum sulfur levels of 0.010%. This datasheet provides information on composition. It also includes information on machining and joining. Filing Code: TS-550. Producer or source: Lukens Steel Company.