This specification covers parts produced from iron phosphorous powder metallurgy materials. These parts are used in magnetic applications requiring higher permeability and electrical resistivity and lower coercive force than attainable routinely from parts produced from iron powder. Two powder types are covered; Type I containing nominally 0.45% phosphorus, and Type II containing nominally 0.8% phosphorus. This specification deals with P/M parts in the sintered or annealed condition. Should the sintered parts be subjected to any secondary operation that causes mechanical strain, such as machining or sizing, they should be re-sintered or annealed.The values stated in either customary (cgs-emu and inch-pound) units or SI units are to be regarded seperately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from two systems may result in nonconformance with this specification.
ANSI/ASTM A839:1997 history
1997ANSI/ASTM A839:1997 Specification for Iron-Phosphorus Powder Metallurgy (P/M) Parts for Soft Magnetic Applications