ASTM WK26954

    New Specification for Sintered Samarium Cobalt (SmCo) Permanent Magnets

    (What is a Work Item?)

    Developed by Subcommittee: A06.02 | Committee A06 | Contact Staff Manager


    1. Scope

    1.1 This specification covers technically important, commercially available, magnetically hard-sintered Samarium cobalt (SmCo) permanent magnets. These materials are available in two general composition families abbreviated SmCo 1:5 and SmCo 2:17. The numbers indicate the approximate atomic ratio of Samarium to the sum of other constituents. 1.2 SmCo magnets have approximate magnetic properties of residual magnetic induction, Br, from 7800 G (0.78 T) up to 12 300 G (1.23 T) and intrinsic coercive field strength, Hci, typically greater than 10 000 Oe (800 kA/m). Special grades and isotropic (un-aligned) magnets can have properties outside these ranges. Specific magnetic hysteresis behavior (demagnetization curve) can be characterized using Test Method A977/A977M. 1.3 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units which are provided for information only and are not considered standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

    ASTM does not have a material specification for these technologically and commercially important magnet materials. Users include government agencies, magnet manufacturers, motor manufacturers, loudspeaker manufacturers, military/aerospace industry, and other users of high-energy permanent magnets.


    Samarium cobalt magnet; sintered rare earth magnet; permanent magnet; coercive field strength; magnetic induction; magnetic properties; permanent magnet

    The title and scope are in draft form and are under development within this ASTM Committee.

    Citing ASTM Standards
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    Work Item Status

    Date Initiated:

    Technical Contact:
    Steve Constantinides


    A06 (16-02)

    Ballot Item Approved as A1102-2016 and Pending Publication