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

Status
Published
Publication Date
31-Mar-2021

Relations

Effective Date
01-May-2012
Effective Date
01-Jun-2006
Effective Date
10-May-2001

Overview

ASTM B780-16(2021) is the internationally recognized standard specification for an electrical contact alloy composed of 75% silver, 24.5% copper, and 0.5% nickel. Developed and maintained by ASTM International, this standard applies to the production and quality assurance of the alloy in forms such as rod, wire, strip, and sheet. The specification establishes chemical composition, permissible impurity levels, and mechanical property requirements to ensure high electrical and physical performance for critical applications.

This standard is widely used in the manufacturing and procurement of precious metal electrical contact materials, providing guidance on inspection, testing, and consistent quality delivery. The standard was prepared following global principles of international standardization as endorsed by the WTO Technical Barriers to Trade (TBT) Committee.

Key Topics

  • Material Composition

    • Silver: 74.0% - 76.0%
    • Copper: Minimum 23.5%, with remainder reported by difference
    • Nickel: 0.35% - 0.65%
    • Controlled levels of impurities such as zinc (max 0.06%), iron (max 0.05%), cadmium (max 0.01%), and lead (max 0.03%), with a total maximum impurity content of 0.15%
  • Forms and Finishing Operations

    • Alloy available as rod, wire, strip, and sheet
    • Finished by cold working, heat treatment, annealing, turning, grinding, or pickling to meet prescribed mechanical and chemical properties
  • Mechanical Properties

    • Mechanical tests include tensile strength, area reduction, elongation, and Rockwell hardness, all evaluated at room temperature
    • Typical tensile strength ranges and mechanical values are prescribed for various alloy tempers and product forms
  • Safety and International Compliance

    • Users must comply with all applicable safety, health, and environmental practices
    • Conforms with international trade and standardization guidelines

Applications

The 75% Silver, 24.5% Copper, 0.5% Nickel electrical contact alloy is designed for high-performance electrical contact applications due to its:

  • High Electrical Conductivity

    • Well-suited for contacts in relays, switches, and circuit breakers where conductivity and resistance to arcing are critical
  • Mechanical Strength and Durability

    • Provides good wear resistance and thermal stability, extending the service life of contact components
  • Precision Manufacturing

    • The stringent composition and mechanical property requirements make this alloy ideal for industries demanding consistent, high-quality electrical conductors

Common application sectors include power distribution, automotive electrical systems, telecommunications, and electronics manufacturing, where reliable electrical performance is essential for safety and efficiency.

Related Standards

To ensure compatibility and comprehensive quality control, ASTM B780-16(2021) references and aligns with several related standards:

  • ASTM B476: General Requirements for Wrought Precious Metal Electrical Contact Materials, detailing broader criteria for precious and semi-precious contact alloys

Users are encouraged to consult these associated standards for further guidance on detailed testing methods, ordering information, and additional specifications relevant to electrical contact materials.

Keywords: ASTM B780, silver copper nickel alloy, electrical contact alloy, precious metal contacts, high-conductivity alloys, mechanical properties, impurity control, standard specification, ASTM standards, electrical contacts

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ASTM B780-16(2021) - Standard Specification for 75 % Silver, 24.5 % Copper, 0.5 % Nickel Electrical Contact Alloy

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Frequently Asked Questions

ASTM B780-16(2021) is a technical specification published by ASTM International. Its full title is "Standard Specification for 75 % Silver, 24.5 % Copper, 0.5 % Nickel Electrical Contact Alloy". This standard covers: 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.

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.

ASTM B780-16(2021) is classified under the following ICS (International Classification for Standards) categories: 77.120.99 - Other non-ferrous metals and their alloys. The ICS classification helps identify the subject area and facilitates finding related standards.

ASTM B780-16(2021) has the following relationships with other standards: It is inter standard links to ASTM B476-01(2012), ASTM B476-01(2006), ASTM B476-01. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.

ASTM B780-16(2021) is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.

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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