ASTM B628-98(2016)

Standard Specification for Silver-Copper Eutectic Electrical Contact Alloy

ABSTRACT
This specification covers 72% silver-28% copper (eutectic) alloy rod, wire, strip, and sheet material for electrical contacts. The material shall be finished by such operations (cold working, heat treatment, annealing, turning, grinding, or pickling) as are required to produce the prescribed properties. The alloy materials shall conform to the chemical composition and mechanical property requirements. All tests shall be conducted at room temperature.
SCOPE
1.1 This specification covers 72 % silver-28 % copper (eutectic) alloy rod, wire, strip, and sheet material for 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 and health practices, and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Apr-2016
• 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)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:B628 −98 (Reapproved 2016)
Standard Specification for
1
Silver-Copper Eutectic Electrical Contact Alloy
This standard is issued under the fixed designation B628; 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 4. Manufacture
1.1 This specification covers 72% silver-28% copper (eu- 4.1 Raw materials shall be of such quality and purity that
tectic) alloy rod, wire, strip, and sheet material for electrical thefinishedproductwillhavethepropertiesandcharacteristics
contacts. prescribed in this specification.
1.2 Thevaluesstatedininch-poundunitsaretoberegarded 4.2 The material shall be finished by such operations (cold
as standard. The values given in parentheses are mathematical working, heat treating, annealing, turning, grinding, or pick-
conversions to SI units that are provided for information only ling) as are required to produce the prescribed properties.
and are not considered standard.
5. Chemical Composition
1.3 This standard does not purport to address all of the
5.1 Materialproducedunderthespecificationshallconform
safety concerns, if any, associated with its use. It is the
to the requirements as to chemical composition prescribed in
responsibility of the user of this standard to become familiar
Table 1.
with all hazards including those identified in the appropriate
Safety Data Sheet (SDS) for this product/material as provided
6. Mechanical Requirements
by the manufacturer, to establish appropriate safety and health
6.1 The material shall conform to the mechanical properties
practices, and determine the applicability of regulatory limi-
prescribed in Table 2 or Table 3.
tations prior to use.
6.2 All test specimens shall be full thickness or diameter
2. Referenced Documents
when practical.
2
2.1 ASTM Standards:
6.3 Alltestsaretobeconductedatroomtemperature,about
B277Test Method for Hardness of Electrical Contact Mate-
68°F (20°C).
rials
7. Inspection and Testing
B476Specification for General Requirements for Wrought
Precious Metal Electrical Contact Materials
7.1 Material furnished under this specification shall be
inspected by the manufacturer as detailed in the applicable
3. General Requirements
provisions of Specification B476 and as listed below.
7.1.1 Visual inspection at 10×.
3.1 SpecificationB476andTestMethodB277shallapplyto
7.1.2 Temper test (hardness or tension, but not both). A
all materials produced to this specification.
tensiontestisrecommendedforstripbelow0.030-in.(0.8-mm)
thickness and for wire of any diameter. A tension test is
1
This specification is under the jurisdiction of ASTM Committee B02 on
preferred when permitted by part size and quantity.
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
7.1.3 Dimensional tests.
B02.05 on Precious Metals and Electrical Contact Materials.
7.1.4 Spectrographic or chemical analysis when indicated
Current edition approved May 1, 2016. Published May 2016. Originally
by the purchase order.
approved in 1977. Last previous edition approved in 2010 as B628–98(2010).
DOI: 10.1520/B0628-98R16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 8. Keywords
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
8.1 composition; electrical contacts; impurities; precious
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. metals; silver copper alloy
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
B628−98 (2016)
A
TABLE 1 Chemical Composition
Element Weight %
Silver 71.0 to 73.0
Copper balance
Total of all impurities 0.15
Zinc 0.06 max
Iron 0.05 max
Cadmium 0.05 max
Lead 0.03 max
Nickel 0.01 max
Aluminum 0.005 max
Phosphorus 0.03 max
Total others 0.06 max
A
Analysis is regularly made for the elements for which specific limits are listed. If,
however, the presence of “other” elements is suspected or indicated in the course
of routine analysis, further analysis shall be made to determine that the total of
these “other” elements and the listed impurities are not in excess of the total
impurities limit.
TABLE 2 Mechanical Properties of Sheet and Strip
Reduction inB&S Percent Ultimate Tensile Strength, psi (MPa) Minimum
Hardness,
Temper Numbers Reduction Elongation
Rockwell 30 T
Minimum Maximum
(Reference) (Reference) in2in.,%
A 0 0 45 000 55 000 15 56–64
(310) (380)
1 ⁄ 4H 1 11 56 000 66 000 7 61–69
(390) (460)
1 ⁄ 2H 2 21 6
...

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: B628 − 98 (Reapproved 2010) B628 − 98 (Reapproved 2016)
Standard Specification for
1
Silver-Copper Eutectic Electrical Contact Alloy
This standard is issued under the fixed designation B628; 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 72 % silver-28 % copper (eutectic) alloy rod, wire, strip, and sheet material for 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 Material Safety Data
Sheet (MSDS)(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.
2. Referenced Documents
2
2.1 ASTM Standards:
B277 Test Method for Hardness of Electrical Contact Materials
B476 Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials
3. General Requirements
3.1 Specification B476 and Test Method B277 shall apply to all materials produced to this specification.
4. Manufacture
4.1 Raw materials shall be of such quality and purity that the finished product will have the properties and characteristics
prescribed in this specification.
4.2 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.
5. Chemical Composition
5.1 Material produced under the specification shall conform to the requirements as to chemical composition prescribed in Table
1.
6. Mechanical Requirements
6.1 The material shall conform to the mechanical properties prescribed in Table 2 or Table 3.
6.2 All test specimens shall be full thickness or diameter when practical.
6.3 All tests are to be conducted at room temperature, about 68°F (20°C).
7. Inspection and Testing
7.1 Material furnished under this specification shall be inspected by the manufacturer as detailed in the applicable provisions
of Specification B476 and as listed below.
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 Oct. 1, 2010May 1, 2016. Published October 2010May 2016. Originally approved in 1977. Last previous edition approved in 20042010 as
B628 – 98 (2004).(2010). DOI: 10.1520/B0628-98R10.10.1520/B0628-98R16.
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’sstandard’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 ----------------------
B628 − 98 (2016)
A
TABLE 1 Chemical Composition
Element Weight %
Silver 71.0 to 73.0
Copper balance
Total of all impurities 0.15
Zinc 0.06 max
Iron 0.05 max
Cadmium 0.05 max
Lead 0.03 max
Nickel 0.01 max
Aluminum 0.005 max
Phosphorus 0.03 max
Total others 0.06 max
A
Analysis is regularly made for the elements for which specific limits are listed. If,
however, the presence of “other” elements is suspected or indicated in the course
of routine analysis, further analysis shall be made to determine that the total of
these “other” elements and the listed impurities are not in excess of the total
impurities limit.
TABLE 2 Mechanical Properties of Sheet and Strip
Reduction in B & S Percent Ultimate Tensile Strength, psi (MPa) Minimum
Hardness,
Temper Numbers Reduction Elongation
Rockwell 30 T
Minimum Maximum
(Reference) (Reference) in 2 in., %
A 0 0 45 000 55 000 15 56–64
(310) (380)
1 ⁄ 4H 1 11 56 000 66 000 7 61–69
(390) (460)
1 ⁄ 2H 2 21 60 000 70 000 3 64–7
...