ASTM B477-21

Standard Specification for Gold-Silver-Nickel Electrical Contact Alloy

ABSTRACT
This specification covers gold-silver-nickel alloy tubing, rod, wire, strip, and sheet material for sliding electrical contacts. Raw materials shall be of such quality and purity that the finished product will have the properties and characteristics prescribed in this specification. The material shall be finished by cold working, heat treating, annealing, turning, grinding, or pickling as are required to produce the prescribed properties. Material produced shall meet the chemical composition requirements. Mechanical properties such as tensile strength, elongation, Knoop hardness, microhardness, as well as the electrical contact shall conform to the prescribed specification.
SCOPE
1.1 This specification covers 75 % gold-22 % silver-3 % nickel alloy tubing, rod, wire, strip, and sheet material for sliding electrical contacts.  
1.2 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.  
1.3 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, health, and environmental practices, and determine the applicability of regulatory limitations prior to use.  
1.4 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2021
• ICS: 77.120.99 - Other non-ferrous metals and their alloys
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.05 - Precious Metals and Electrical Contact Materials and Test Methods

Standards Content (Sample)

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.
Designation:B477 −21
Standard Specification for
1
Gold-Silver-Nickel Electrical Contact Alloy
This standard is issued under the fixed designation B477; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 3. Manufacture
3.1 Raw materials shall be of such quality and purity that
1.1 This specification covers 75% gold-22% silver-3%
thefinishedproductwillhavethepropertiesandcharacteristics
nickel alloy tubing, rod, wire, strip, and sheet material for
prescribed in this specification.
sliding electrical contacts.
3.2 The material shall be finished by such operations (cold
1.2 The values stated in inch-pound units are to be regarded
working, heat treating, annealing, turning, grinding, or pick-
as standard. The values given in parentheses are mathematical
ling) as are required to produce the prescribed properties.
conversions to SI units that are provided for information only
4. Chemical Composition
and are not considered standard.
4.1 Materialproducedunderthespecificationshallmeetthe
1.3 This standard does not purport to address all of the
requirements of chemical composition prescribed in Table 1.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to become familiar
5. Mechanical and Electrical Requirements
with all hazards including those identified in the appropriate
5.1 The contract or order may specify ultimate tensile
Safety Data Sheet (SDS) for this product/material as provided
strength and elongation, microhardness (Knoop orVickers), or
by the manufacturer, to establish appropriate safety, health,
a combination of these mechanical properties as temper crite-
and environmental practices, and determine the applicability
rion.Ifthecontractororderdoesnotspecifyatempercriterion,
of regulatory limitations prior to use.
then the criterion for temper designation will be ultimate
1.4 This international standard was developed in accor- tensile strength and elongation.
dance with internationally recognized principles on standard-
5.2 Mechanical properties shall conform to the listings of
ization established in the Decision on Principles for the
Table 2.
Development of International Standards, Guides and Recom-
5.3 All test specimens shall be full size when practical.
mendations issued by the World Trade Organization Technical
5.4 Alltestsaretobeconductedatroomtemperature,about
Barriers to Trade (TBT) Committee.
68°F (20°C).
2. Referenced Documents
6. General Requirements
2
2.1 ASTM Standards:
6.1 Specification B476 shall apply to all materials produced
to this specification.
B476Specification for General Requirements for Wrought
Precious Metal Electrical Contact Materials
6.2 Microhardness, when performed, shall be in accordance
E384Test Method for Microindentation Hardness of Mate-
with Test Method E384.
rials
7. Inspection and Testing
7.1 Material furnished under this specification shall be
inspected by the manufacturer as listed below:
1
This specification is under the jurisdiction of ASTM Committee B02 on
7.1.1 Visual inspection at 10×,
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
B02.05 on Precious Metals and Electrical Contact Materials.
7.1.2 Temper test (hardness or tensile),
Current edition approved Nov. 1, 2021. Published December 2021. Originally
7.1.3 Dimensional tests, and
approved in 1968. Last previous edition approved in 2017 as B477–97(2017).
7.1.4 Spectrographic or chemical analysis when indicated
DOI: 10.1520/B0477-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or by the purchase order.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
7.2 Thepurchasershallperformsuchtestsasarerequiredto
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. verify the quality of material procured under this specification.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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B477−21
TABLE 1 Chemical Composition
Element Weight Percent
Gold 74.2–75.8
Silver 21.4–22.6
Nickel 2.6–3.4
Selected base metals (lead, antimony, bismuth, tin, 0.01 max, total
arsenic, cadmium, germanium, thallium,
gallium, sulfur)
Total all base metal impurities (including above selected 0.2 max
base metals
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B477 − 97 (Reapproved 2017) B477 − 21
Standard Specification for
1
Gold-Silver-Nickel Electrical Contact Alloy
This standard is issued under the fixed designation B477; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This specification covers 75 % gold-22 % silver-3 % nickel alloy tubing, rod, wire, strip, and sheet material for sliding
electrical contacts.
1.2 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.
1.3 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 safety, health, and healthenvi-
ronmental practices, and determine the applicability of regulatory limitations prior to use.
1.4 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
2
2.1 ASTM Standards:
B476 Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials
E384 Test Method for Microindentation Hardness of Materials
3. Manufacture
3.1 Raw materials shall be of such quality and purity that the finished product will have the properties and characteristics
prescribed in this specification.
3.2 The material shall be finished by such operations (cold working, heat treating, annealing, turning, grinding, or pickling) as are
required to produce the prescribed properties.
4. Chemical Composition
4.1 Material produced under the specification shall meet the requirements of chemical composition prescribed in Table 1.
1
This specification is under the jurisdiction of ASTM Committee B02 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.05 on
Precious Metals and Electrical Contact Materials.
Current edition approved April 1, 2017Nov. 1, 2021. Published April 2017December 2021. Originally approved in 1968. Last previous edition approved in 20122017 as
B477 – 97 (2012).(2017). DOI: 10.1520/B0477-97R17.10.1520/B0477-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
B477 − 21
TABLE 1 Chemical Composition
Element Weight Percent
Gold 74.2–75.8
Silver 21.4–22.6
Nickel 2.6–3.4
Selected base metals (lead, antimony, bismuth, tin, 0.01 max, total
arsenic, cadmium, germanium, thallium,
gallium, sulfur)
Total all base metal impurities (including above selected 0.2 max
base metals)
Total noble metal impurities 0.1 max
5. Mechanical and Electrical Requirements
5.1 The contract or order may specify ultimate tensile strength and elongation, microhardness (Knoop or Vickers), or a
combination of these mechanical properties as temper criterion. If the contract or order does not specify a temper criterion, then
the criterion for temper designation will be ultimate tensile strength and elongation.
5.2 Mechanical properties shall conform to the listings of Table 2.
5.3 All test specimens shall be full size when practical.
5.4 All tests are to be conducted at room temperature, about 68°F (20°C).
6. General Requirements
6.1 Specification B476 shall apply to all materials produced to this specification.
6.2 Microhardness, when performed, shall be in accordance with Test Method E384.
7. Inspection and Testing
7.1 Material furnished under this specification shall be inspected by the manufacturer as listed below:
7.1
...