ASTM B780-16(2021)
(Specification)Standard Specification for 75 % Silver, 24.5 % Copper, 0.5 % Nickel Electrical Contact Alloy
Standard Specification for 75 % Silver, 24.5 % Copper, 0.5 % Nickel Electrical Contact Alloy
ABSTRACT
This specification covers electrical contact alloys with the nominal composition of 75% silver, 24.5% copper, and 0.5% nickel in the form of rods, wires, strips, and sheets. Raw materials shall be of such quality and purity that the products, which shall be finished by such operations as cold working, heat treatment, annealing, turning, grinding, or pickling, shall adhere to the chemical composition and mechanical property requirements prescribed here. Besides analysis for the elements silver, copper, and nickel, further analysis is to be made for suspected or indicated impurities, such as zinc, iron, cadmium, and lead, to make sure that their total does not exceed specified limits. Mechanical tests, which are to be conducted at room temperature, shall evaluate the materials' tensile strength, elongation, Rockwell hardness, and area and thickness reduction.
SCOPE
1.1 This specification covers an electrical contact material with the nominal composition of 75 % silver, 24.5 % copper, and 0.5 % nickel in the form of rod, wire, strip, and sheet.
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
Relations
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:B780 −16 (Reapproved 2021)
Standard Specification for
75% Silver, 24.5% Copper, 0.5% Nickel Electrical Contact
Alloy
This standard is issued under the fixed designation B780; 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. Materials and Manufacture
1.1 This specification covers an electrical contact material 4.1 Raw materials shall be of such quality and purity that
with the nominal composition of 75% silver, 24.5% copper, thefinishedproductwillhavethepropertiesandcharacteristics
and 0.5% nickel in the form of rod, wire, strip, and sheet. 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 Materialproducedunderthisspecificationshallconform
safety concerns, if any, associated with its use. It is the
to the chemical composition limits prescribed in Table 1.
responsibility of the user of this standard to become familiar
with all hazards including those identified in the appropriate
5.2 These specification limits do not preclude the possible
Safety Data Sheet (SDS) for this product/material as provided
presence of other unnamed elements, impurities, or additives.
by the manufacturer, to establish appropriate safety, health,
Analysis shall be regularly made only for the minor elements
and environmental practices, and determine the applicability listed in the table. However, if a user knows of elements that
of regulatory limitations prior to use.
might be detrimental to their application or has other reasons
1.4 This international standard was developed in accor- for requiring analysis for specific elements, then agreement
dance with internationally recognized principles on standard-
between manufacturer and purchaser for both limits and
ization established in the Decision on Principles for the
methods of analysis should be required for elements not
Development of International Standards, Guides and Recom-
specified.
mendations issued by the World Trade Organization Technical
6. Mechanical Properties
Barriers to Trade (TBT) Committee.
6.1 Thematerialshallconformtotheapplicablemechanical
2. Referenced Documents
properties prescribed in Table 2 or Table 3.
2.1 ASTM Standards:
6.2 Alltestspecimensshallbethefullthicknessordiameter
B476Specification for General Requirements for Wrought
as the size supplied when practical. The test procedures shall
Precious Metal Electrical Contact Materials
follow the ASTM specifications referred to in Specification
B476.
3. Ordering Information
6.3 Alltestsaretobeconductedatroomtemperature,about
3.1 Refer to Specification B476.
68°F (20°C).
7. Inspection, Rejection and Rehearing, Certification,
This specification is under the jurisdiction of ASTM Committee B02 on
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee Product Marking, and Supplementary Requirements
B02.05 on Precious Metals and Electrical Contact Materials.
7.1 Material furnished to this specification shall meet the
Current edition approved April 1, 2021. Published April 2021. Originally
approved in 1987. Last previous edition approved in 2016 as B780–16. DOI: requirements listed in Sp
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