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    ASTM B476 - 01(2017)

    Standard Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials

    Active Standard ASTM B476 | Developed by Subcommittee: B02.05

    Book of Standards Volume: 02.04

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    This specification covers general requirements common to wrought precious metal electrical contact alloy products in the form of sheet, strip, wire, and rod. The raw material shall be of such quality and purity that the finished product shall have the properties and characteristics prescribed in the applicable product specification. The product shall be produced by a combination of hot or cold working operations, it shall be finished, unless otherwise specified, by cold working, annealing, or heat treatment as may be necessary to meet the specified properties. Surfaces of all material furnished to this specification shall be smooth, clean, and free from scratches, stains, rough spots, slivers, laps, scale, pits, and any other injurious defects. Test methods such as chemical analysis and physical tests shall be performed accordingly.

    This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

    Significance and Use

    11.1 For purpose of determining compliance with the specified limits for requirements of the properties listed in the following table, an observed value or a calculated value shall be rounded as indicated in accordance with Practice E29.



    Rounded Unit
    for Observed or
    Calculated Value

    Chemical composition



    Knoop (100-g load unless other-
      wise specified)
    Vicker (specify load)
    Rockwell (all scales, specify which)
    Rockwell superficial (all scales,
      specify which)


    nearest unit on the last right
     hand place of figure of
     specified limit




     Tensile strength

     psi (MPa)

    nearest 1000 psi (nearest 10

     Yield Strength

     psi (MPa)

    nearest 1000 psi (nearest
     10 MPa)




     Below 5 %


    nearest multiple of 0.5 %

     5 % and over


    nearest 1 %

    Grain size



     Up to 0.055 mm  incl.


    nearest multiple of  0.005

     Over 0.055 to 0.160, mm, incl.


    nearest 0.01 mm

    1. Scope

    1.1 This specification covers general requirements common to wrought precious metal electrical contact alloy products in the form of sheet, strip, wire, and rod. Unless otherwise specified in the purchase order or in an individual specification, these general requirements shall apply to wrought electrical contact materials where indicated in the applicable product specifications issued by ASTM.

    1.2 In case of conflict, the requirements on the purchase order, the individual specification, and this general specification shall prevail in the sequence named.

    1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use.

    1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    B63 Test Method for Resistivity of Metallically Conducting Resistance and Contact Materials

    B772 Guide for Specifying the Chemical Compositions for Electrical Contact Materials (Arcing and Nonarcing)

    E3 Guide for Preparation of Metallographic Specimens

    E8 Test Methods for Tension Testing of Metallic Materials

    E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

    E55 Practice for Sampling Wrought Nonferrous Metals and Alloys for Determination of Chemical Composition

    E112 Test Methods for Determining Average Grain Size

    E384 Test Method for Microindentation Hardness of Materials

    ICS Code

    ICS Number Code 77.120.99 (Other non-ferrous metals and their alloys)

    UNSPSC Code

    UNSPSC Code

    Referencing This Standard
    Link Here
    Link to Active (This link will always route to the current Active version of the standard.)

    DOI: 10.1520/B0476-01R17

    Citation Format

    ASTM B476-01(2017), Standard Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials, ASTM International, West Conshohocken, PA, 2017, www.astm.org

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