ASTM B702-93(2015)
(Specification)Standard Specification for Copper-Tungsten Electrical Contact Material
Standard Specification for Copper-Tungsten Electrical Contact Material
ABSTRACT
This specification covers electrical contact components made from copper tungsten by powder metallurgical procedures. The material shall conform to the chemical composition limits as agreed upon between the manufacturer and the user using the newest edition of Annual Book of ASTM standards, or any other approved method agreed upon. Qualification tests for determination of physical properties shall be performed on production parts, wherever practical or applicable. The tests shall be determined after consideration of the function of the part.
SCOPE
1.1 This specification covers electrical contact components made from copper tungsten by powder metallurgical procedures.
1.2 This specification covers compositions within the copper tungsten system normally specified by users of contacts.
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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 Data Safety 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.
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Designation:B702 −93 (Reapproved 2015)
Standard Specification for
Copper-Tungsten Electrical Contact Material
This standard is issued under the fixed designation B702; 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.
1. Scope bounce, environmental variations, assembly technique and
variations, etc.) this specification cannot ensure performance
1.1 This specification covers electrical contact components
control in the application.As part of the qualification on initial
made from copper tungsten by powder metallurgical proce-
samples it is recommended that the user functionally electri-
dures.
cally test the materials for all devices applicable to the
1.2 This specification covers compositions within the cop-
material’s use. This specification will provide a means for the
per tungsten system normally specified by users of contacts.
contact manufacturer and contact user to reach agreement on
the details of material to be supplied for a specified use and
1.3 The values stated in inch-pound units are to be regarded
as standard. No other units of measurement are included in this reasonable assurance that future lots will be similar in proper-
ties and microstructure to the initial test or sample contacts
standard.
supplied.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Ordering Information
responsibility of the user of this standard to become familiar
with all hazards including those identified in the appropriate 4.1 Orders for this material under this specification shall
Data Safety Sheet (SDS) for this product/material as provided include the following information:
by the manufacturer, to establish appropriate safety and health 4.1.1 Dimensions (see Section 8),
practices, and determine the applicability of regulatory limi- 4.1.2 Chemical composition (see reference tables in Related
tations prior to use. Material as possible guideline),
4.1.3 Physical properties (see Section 6 and reference tables
2. Referenced Documents
as guideline),
4.1.4 Certification (see Section 11), and
2.1 ASTM Standards:
4.1.5 Other features as agreed upon between the vendor and
B328 Test Method for Density, Oil Content, and Intercon-
the user.
nected Porosity of Sintered Metal Structural Parts and
Oil-Impregnated Bearings (Withdrawn 2009)
5. Chemical Requirements
3. Significance and Use
5.1 The material shall conform to composition limits as
agreed upon between the manufacturer and the user.
3.1 Proprietary methods for manufacture of these materials
varysignificantlyamongsuppliersandthesemethodsinfluence
5.2 The chemical analysis shall be made in accordance with
such properties as arc erosion, contact resistance, and tendency
the methods prescribed in the newest edition of Annual Book of
to weld in service. Since the performance of contacts in a
ASTM Standards, or by any other approved method agreed
device depends on numerous factors outside the contact itself
upon between the manufacturer and the purchaser.
(opening speed, closing speed, contact pressure, contact
6. Other Properties
6.1 The manufacturer and the purchaser shall agree on
This specification is under the jurisdiction of ASTM Committee B02 on
qualification tests for determination of physical properties.
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
B02.05 on Precious Metals and Electrical Contact Materials.
6.2 The tests shall be performed on production parts,
Current edition approved Oct. 1, 2015. Published October 2015. Originally
wherever practical or applicable. (Small size contacts do not
approved in 1982. Last previous edition approved in 2010 as B702 – 93 (2010).
DOI: 10.1520/B0702-93R15. lend themselves to accurate conductivity measurement.)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.3 The tests shall be determined after consideration of the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on function of the part.
the ASTM website.
6.4 The typical properties of five most common types of
The last approved version of this historical standard is referenced on
www.astm.org. copper-tungsten contacts are given in Appendix X1.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B702−93 (2015)
7. Dimensions and Permissible Variations listed in the table. However, if a user knows of elements that
might be detrimental to their application or has other reasons
7.1 Permissible variations in dimensions shall be within the
for requiring analysis for specific elements, then agreement
limits specified on drawings describing the contacts and
between manufacturer and purchaser for both limits and
accompanying the order, or shall be within the limits specified
methods of analysis should be required for elements not
in the purchase order.
specified.
8. Workmanship, Finish, and Appearance
9.3 Physical Tests—The manufacturer and the purchaser
8.1 The parts shall be free of defects in material or shall agree on a representative number of specimens for
physical tests including microstructure.
processing, which would seriously affect their performance.
9. Sampling and Inspection
10. Rejection and Rehearing
9.1 Lot—Unless otherwise specified, a lot shall consist of 10.1 Unless otherwise specified, rejections based on
...
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: B702 − 93 (Reapproved 2010) B702 − 93 (Reapproved 2015)
Standard Specification for
Copper-Tungsten Electrical Contact Material
This standard is issued under the fixed designation B702; 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.
1. Scope
1.1 This specification covers electrical contact components made from copper tungsten by powder metallurgical procedures.
1.2 This specification covers compositions within the copper tungsten system normally specified by users of contacts.
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this
standard.
1.4 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 Data Safety
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
2.1 ASTM Standards:
B328 Test Method for Density, Oil Content, and Interconnected Porosity of Sintered Metal Structural Parts and Oil-Impregnated
Bearings (Withdrawn 2009)
3. Significance and Use
3.1 Proprietary methods for manufacture of these materials vary significantly among suppliers and these methods influence such
properties as arc erosion, contact resistance, and tendency to weld in service. Since the performance of contacts in a device depends
on numerous factors outside the contact itself (opening speed, closing speed, contact pressure, contact bounce, environmental
variations, assembly technique and variations, etc.) this specification cannot ensure performance control in the application. As part
of the qualification on initial samples it is recommended that the user functionally electrically test the materials for all devices
applicable to the material’s use. This specification will provide a means for the contact manufacturer and contact user to reach
agreement on the details of material to be supplied for a specified use and reasonable assurance that future lots will be similar in
properties and microstructure to the initial test or sample contacts supplied.
4. Ordering Information
4.1 Orders for this material under this specification shall include the following information:
4.1.1 Dimensions (see Section 8),
4.1.2 Chemical composition (see reference tables in Related Material as possible guideline),
4.1.3 Physical properties (see Section 6 and reference tables as guideline),
4.1.4 Certification (see Section 11), and
4.1.5 Other features as agreed upon between the vendor and the user.
5. Chemical Requirements
5.1 The material shall conform to composition limits as agreed upon between the manufacturer and the user.
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, 2010Oct. 1, 2015. Published October 2010October 2015. Originally approved in 1982. Last previous edition approved in 20042010 as
B702 – 93 (2004).(2010). DOI: 10.1520/B0702-93R10.10.1520/B0702-93R15.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B702 − 93 (2015)
5.2 The chemical analysis shall be made in accordance with the methods prescribed in the newest edition of Annual Book of
ASTM Standards, or by any other approved method agreed upon between the manufacturer and the purchaser.
6. Other Properties
6.1 The manufacturer and the purchaser shall agree on qualification tests for determination of physical properties.
6.2 The tests shall be performed on production parts, wherever practical or applicable. (Small size contacts do not lend
themselves to accurate conductivity measurement.)
6.3 The tests shall be determined after consideration of the function of the part.
6.4 The typical properties of five most common types of copper-tungsten contacts are given in Appendix X1.
7. Dimensions and Permissible Variations
7.1 Permissible variations in dimensions shall be within the limits specified on drawings describing the contacts and
accompanying the order, or shall be within the limits specified in the purchase order.
8. Workmanship, Finish, and Appearance
8.1 The parts shall be free of defects in material or processing, which would seriously affect their performance.
9. Sampling and Inspection
9.1 Lot—Unless otherwise specified, a lot shall consist of parts of the same form, and dimensions, made of powders of the same
particle size range and composition, processed under the same conditions, and submitted for inspection at one time.
9.2 Chemical Analysis—At least one sample for chemical analysis shall be taken from each lot. A representative sample of chips
may be obtained by milling, drilling, or crushing at least two pieces with dry tools, without lub
...
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