American Society for Testing and Materials (ASTM). Current edition approved Dec. 1, 2006. Published January 2007. Originally approved in 1970. Last previous edition addition approved in 2003 as B 637 – 03. 6 p. This specification covers hot- and cold-worked precipitation-hardenable nickel alloy rod, bar, forgings, and forging stock for high-temperature service (Table 1).