ASTM B685-20

Standard Specification for Palladium-Copper Electrical Contact Material

ABSTRACT
This specification deals with the standard requirements for palladium-copper alloy in the form of rod, wire, strip, and sheet material for use in electrical contacts. The specimen shall be produced from raw materials of such quality and purity by cold working, annealing, turning, grinding, or pickling. Material shall meet the chemical composition requirements for palladium, copper, silver, iron, zinc, cadmium, lead, and aluminum which shall be determined by spectrographic or chemical analysis. Temper test (hardness or tension) shall be conducted to determine the mechanical properties which shall be in conformity with the ultimate tensile strength, elongation, Knoop or Vickers microhardness, and Rockwell or Rockwell superficial hardness specifications. Visual examination shall be done on the furnished materials.
SCOPE
1.1 This specification covers a 60 % palladium-40 % copper alloy in the form of 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) 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-2020
• 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

Relations

• Replaces: ASTM B685-01(2012) - Standard Specification for Palladium-Copper Electrical Contact Material
• Effective Date: 01-Apr-2020
• Refers: ASTM B542-13(2019) - Standard Terminology Relating to Electrical Contacts and Their Use
• Effective Date: 01-Nov-2019
• Refers: ASTM B542-13 - Standard Terminology Relating to Electrical Contacts and Their Use
• Effective Date: 01-Feb-2013
• Refers: ASTM B476-01(2012) - Standard Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials
• Effective Date: 01-May-2012
• Refers: ASTM B542-07 - Standard Terminology Relating to Electrical Contacts and Their Use
• Effective Date: 01-May-2007
• Refers: ASTM B476-01(2006) - Standard Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials
• Effective Date: 01-Jun-2006
• Refers: ASTM B542-04 - Standard Terminology Relating to Electrical Contacts and Their Use
• Effective Date: 01-May-2004
• Refers: ASTM B476-01 - Standard Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials
• Effective Date: 10-May-2001
• Refers: ASTM B542-00 - Standard Terminology Relating to Electrical Contacts and Their Use
• Effective Date: 10-Oct-2000

Overview

ASTM B685-20: Standard Specification for Palladium-Copper Electrical Contact Material outlines the critical requirements for a 60% palladium - 40% copper alloy, provided as rod, wire, strip, and sheet, specifically for use in electrical contacts. Developed by ASTM International, this standard defines the chemical composition, manufacturing processes, mechanical property testing, as well as inspection and safety practices to ensure the alloy’s suitability for demanding electrical applications. Adhering to ASTM B685-20 promotes consistency, safety, and reliability in the production and use of palladium-copper contact materials within the electrical industry.

Key Topics

Essential aspects covered by ASTM B685-20 include:

• Material Forms: Specifies requirements for rod, wire, strip, and sheet forms made from palladium-copper alloy.
• Chemical Composition: Defines strict limits for palladium, copper, silver, iron, zinc, cadmium, lead, aluminum, and total impurities.
• Material Quality: Mandates production from high-purity raw materials and approved processes like cold working, annealing, turning, grinding, or pickling.
• Mechanical Properties: Establishes procedures for testing ultimate tensile strength, elongation, microhardness (Knoop or Vickers), and Rockwell hardness.
• Inspection and Quality Control: Requires visual inspection, dimensional testing, and chemical or spectrographic analysis as needed.
• Purchasing Information: Details ordering requirements, including dimensions, alloy composition, certification, and specific property demands.
• Safety and Compliance: Highlights the need for familiarity with hazards and relevant Material Safety Data Sheets (MSDS), and encourages establishing appropriate safety and environmental practices.

Applications

Palladium-copper electrical contact material manufactured according to ASTM B685-20 is widely used in:

• Electrical Connectors and Relays: The alloy’s precise composition and robust mechanical properties ensure long-term, reliable operation in connectors, switches, and relay contacts.
• Interconnect Systems: Palladium-copper alloys are preferred for their resistance to corrosion and stable electrical performance, making them ideal for high-reliability interconnects in telecommunications and data centers.
• Aerospace and Defense Electronics: Meeting rigorous ASTM standards is crucial for mission-critical electrical contacts in avionics, guidance systems, and military electronics.
• Industrial Automation: Control equipment, sensors, and actuators often employ palladium-copper contacts for their consistent performance under repeated cycles of electrical load.
• Precision Instruments: The material’s durability and excellent conductivity are valuable for laboratory equipment, medical devices, and measurement tools.

Related Standards

Several other ASTM standards complement and support the application of ASTM B685-20:

• ASTM B476: General Requirements for Wrought Precious Metal Electrical Contact Materials - Provides overarching manufacturing and test criteria for precious metal contacts, referenced throughout B685-20.
• ASTM B542: Terminology Relating to Electrical Contacts and Their Use - Standardizes definitions critical for the interpretation and application of electrical contact materials.
• ISO and International Standards: While ASTM B685-20 itself is developed according to WTO principles on international standardization, it also aligns with global requirements for electrical contact materials.

By following ASTM B685-20, manufacturers and users can ensure that palladium-copper electrical contact materials consistently meet high standards for purity, performance, and safety, supporting reliability in electrical and electronic applications around the world.

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:B685 −20
Standard Specification for
Palladium-Copper Electrical Contact Material
This standard is issued under the fixed designation B685; 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* 4. General Requirements
1.1 Thisspecificationcoversa60 %palladium-40 %copper 4.1 The requirements of Specification B476 shall apply to
alloy in the form of rod, wire, strip, and sheet material for all materials produced to this specification.
electrical contacts.
5. Ordering Information
1.2 The values stated in inch-pound units are to be regarded
5.1 Include the following information when placing orders
as standard. The values given in parentheses are mathematical
for product under this specification:
conversions to SI units that are provided for information only
5.1.1 Dimensions—Thickness, width, length, diameter, coil
and are not considered standard.
size, or other pertinent sizes;
1.3 This standard does not purport to address all of the
5.1.2 Alloy composition;
safety concerns, if any, associated with its use. It is the
5.1.3 Physical and mechanical properties;
responsibility of the user of this standard to become familiar
5.1.4 Certification; and
with all hazards including those identified in the appropriate
5.1.5 Other features as agreed upon between the seller and
Material Safety Data Sheet (MSDS) for this product/material
the user.
as provided by the manufacturer, to establish appropriate
safety, health, and environmental practices, and determine the
6. Materials and Manufacture
applicability of regulatory limitations prior to use.
6.1 Materials shall be of such quality and purity that the
1.4 This international standard was developed in accor-
finished product will have the properties and characteristics
dance with internationally recognized principles on standard-
prescribed in this specification.
ization established in the Decision on Principles for the
6.2 The material shall be finished by such operations (cold
Development of International Standards, Guides and Recom-
working, annealing, turning, grinding, or pickling) as are
mendations issued by the World Trade Organization Technical
required to produce the required properties.
Barriers to Trade (TBT) Committee.
2. Referenced Documents 7. Chemical Composition
2.1 ASTM Standards: 7.1 Material produced under the specification shall meet the
B476 Specification for General Requirements for Wrought chemical composition requirements specified in Table 1.
Precious Metal Electrical Contact Materials
7.2 By agreement between purchaser and manufacturer,
B542 Terminology Relating to Electrical Contacts and Their
analysis may be required and limits established for elements or
Use
compounds not specified in Table 1.
3. Terminology
8. Mechanical Property Requirements
3.1 For terms related to electrical contacts and their use,
8.1 The contract or order may specify ultimate tensile
refer to Terminology B542.
strength, elongation, microhardness (Knoop or Vickers), hard-
ness (Rockwell or Rockwell Superficial), or a combination of
This specification is under the jurisdiction of ASTM Committee B02 on
these mechanical properties as temper criterion. If the contract
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
or order does not specify a temper criterion, then the criterion
B02.05 on Precious Metals and Electrical Contact Materials.
Current edition approved April 1, 2020. Published April 2020. Originally for temper designation will be ultimate tensile strength and
approved in 1981. Last previous edition approved in 2012 as B685 – 01 (2012).
elongation as listed in Table 2 and Table 3.
DOI: 10.1520/B0685-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 8.2 Mechanical properties shall conform to the listings of
contact ASTM Customer Service at service
...

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: B685 − 01 (Reapproved 2012) B685 − 20
Standard Specification for
Palladium-Copper Electrical Contact Material
This standard is issued under the fixed designation B685; 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 Scope*
1.1 This specification covers a 60 % palladium-40 % copper alloy in the form of 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) for this product/material as provided by the manufacturer, to establish appropriate safety safety, health, and
healthenvironmental 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
2.1 ASTM Standards:
B476 Specification for General Requirements for Wrought Precious Metal Electrical Contact Materials
B542 Terminology Relating to Electrical Contacts and Their Use
3. Terminology
3.1 For terms related to electrical contacts and their use, refer to Terminology B542.
4. General Requirements
4.1 The requirements of Specification B476 shall apply to all materials produced to this specification.
5. Ordering Information
5.1 Include the following information when placing orders for product under this specification:
5.1.1 Dimensions—Thickness, width, length, diameter, coil size, or other pertinent sizes;
5.1.2 Alloy composition;
5.1.3 Physical and mechanical properties;
5.1.4 Certification; and
5.1.5 Other features as agreed upon between the seller and the user.
6. Manufacture Materials and Manufacture
6.1 Raw materials Materials shall be of such quality and purity that the finished product will have the properties and
characteristics prescribed in this specification.
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 May 1, 2012April 1, 2020. Published May 2012April 2020. Originally approved in 1981. Last previous edition approved in 20062012 as
B685 – 01 (2006).(2012). DOI: 10.1520/B0685-01R12.10.1520/B0685-20.
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.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B685 − 20
6.2 The material shall be finished by such operations (cold working, annealing, turning, grinding, or pickling) as are required
to produce the prescribedrequired properties.
7. Chemical Composition
7.1 Material produced under the specification shall meet the requirements of chemical composition prescribed requirements
specified in Table 1.
7.2 By agreement between purchaser and manufacturer, analysis may be required and limits established for elements or
compounds not specified in Table 1the table of chemical composition.
8. Mechanical Property Requirements
8.1 The contract or order may specify ultimate tensile strength, elongation, microhardnes
...