ASTM B 561 - 94 (Reapproved 2005) Standard Specification for Refined Platinum

American Society for Testing and Materials (ASTM). Current edition approved May 1, 2005. Published June 2005. Originally approved in 1972. Last previous edition approved in 1999 as B 561 – 94 (1999). 2 p. This specification covers refined platinum as sponge, cast bar, and wrought forms (Note 1) in two grades as follows:
Grade 99.95 (UNS PO4995)— Platinum having a purity of 99.95 %, min, and
Grade 99.99— Platinum having a purity of 99.99 % min.