ASTM B344-20

Standard Specification for Drawn or Rolled Nickel-Chromium and Nickel-Chromium-Iron Alloys for Electrical Heating Elements

SCOPE
1.1 This specification covers annealed, drawn, or rolled shapes for electrical heating purposes, of alloys having the nominal compositions of 80 % nickel and 20 % chromium; 60 % nickel, 16 % chromium, and remainder iron; and 35 % nickel, 20 % chromium, and remainder iron; 38 % nickel, 21 % chromium, and remainder iron; and 35 % nickel, 20 % chromium remainder iron.  
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: 30-Sep-2020
• ICS: 77.150.40 - Nickel and chromium products
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.10 - Thermostat Metals and Electrical Resistance Heating Materials

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:B344 −20
Standard Specification for
Drawn or Rolled Nickel-Chromium and Nickel-Chromium-
1
Iron Alloys for Electrical Heating Elements
This standard is issued under the fixed designation B344; 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 B63 Test Method for Resistivity of Metallically Conducting
Resistance and Contact Materials
1.1 This specification covers annealed, drawn, or rolled
B70 Test Method for Change of Resistance With Tempera-
shapes for electrical heating purposes, of alloys having the
ture of Metallic Materials for Electrical Heating
nominal compositions of 80 % nickel and 20 % chromium;
B76 Test Method for Accelerated Life of Nickel-Chromium
60 % nickel, 16 % chromium, and remainder iron; and 35 %
and Nickel-Chromium-Iron Alloys for Electrical Heating
nickel,20 %chromium,andremainderiron;38 %nickel,21 %
chromium, and remainder iron; and 35 % nickel, 20 % chro-
3. Significance and Use
mium remainder iron.
3.1 This specification on nickel-chromium and nickel-
1.2 The values stated in inch-pound units are to be regarded
chromium-iron alloys contains the requirements for chemistry,
as standard. The values given in parentheses are mathematical
electrical resistance, mechanical properties, and packaging.
conversions to SI units that are provided for information only
4. Requirements
and are not considered standard.
1.3 This standard does not purport to address all of the 4.1 The alloys shall conform to the requirements as to
safety concerns, if any, associated with its use. It is the chemical composition prescribed in Table 1.
responsibility of the user of this standard to become familiar
4.2 Samples for Chemical Analysis—Specimens for chemi-
with all hazards including those identified in the appropriate
calanalysismaybetakenfromeitherthemeltorfromasample
Safety Data Sheet (SDS) for this product/material as provided
of finished wire that is representative of the lot.
by the manufacturer, to establish appropriate safety, health,
4.2.1 The lot size for determining compliance with the
and environmental practices, and determine the applicability
requirements of this specification shall be one heat.
of regulatory limitations prior to use.
4.3 Chemical Analysis—The chemical analysis shall be
1.4 This international standard was developed in accor-
made in accordance with Test Methods A751, or by other
dance with internationally recognized principles on standard-
analytical methods approved by the purchaser.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 4.4 Actual chemical analysis is not required for routine
mendations issued by the World Trade Organization Technical
acceptance.
Barriers to Trade (TBT) Committee.
5. Physical Requirements
2. Referenced Documents
5.1 The material shall be thoroughly and uniformly an-
2
nealed.
2.1 ASTM Standards:
A751 Test Methods, Practices, and Terminology for Chemi-
5.2 Wire shall conform to the following elongation require-
cal Analysis of Steel Products
ments:
Size Elongation in 10 in.,
min, %
1
This specification is under the jurisdiction of ASTM Committee B02 on
0.0035 in. (0.0889 mm) (No. 39 Awg) and larger 20
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
0.0031 in. (0.0787 mm) to 0.002 in. 10
B02.10 on Thermostat Metals and Electrical Resistance Heating Materials.
(0.0508 mm) (Nos. 40 to 44 Awg)
Current edition approved Oct. 1, 2020. Published October 2020. Originally
approved in 1959. Last previous edition approved in 2014 as B344 – 14. DOI: 5.3 Determination is not required for routine acceptance.
10.1520/B0344-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 6. Nominal Resistivity
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.1 The nominal resistivity (Note 1) shall be the resistivity
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. of the wire as quenched from a temperature above 1450°F
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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B344−20
TABLE 1 Chemical Requirements
Composition, %
Element
80 Nickel-20 Chromium Alloy 60 Nickel-16 Chromium Alloy 38 Nickel-21 Chromi
...

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: B344 − 14 B344 − 20
Standard Specification for
Drawn or Rolled Nickel-Chromium and Nickel-Chromium-
1
Iron Alloys for Electrical Heating Elements
This standard is issued under the fixed designation B344; 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 annealed, drawn, or rolled shapes for electrical heating purposes, of alloys having the nominal
compositions of 80 % nickel and 20 % chromium; 60 % nickel, 16 % chromium, and remainder iron; and 35 % nickel, 20 %
chromium, and remainder iron; 38 % nickel, 21 % chromium, and remainder iron; and 35 % nickel, 20 % chromium remainder
iron.
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.
2. Referenced Documents
2
2.1 ASTM Standards:
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
B63 Test Method for Resistivity of Metallically Conducting Resistance and Contact Materials
B70 Test Method for Change of Resistance With Temperature of Metallic Materials for Electrical Heating
B76 Test Method for Accelerated Life of Nickel-Chromium and Nickel-Chromium-Iron Alloys for Electrical Heating
3. Significance and Use
3.1 This specification on nickel-chromium and nickel-chromium-iron alloys contains the requirements for chemistry, electrical
resistance, mechanical properties, and packaging.
1
This specification is under the jurisdiction of ASTM Committee B02 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.10 on
Thermostat Metals and Electrical Resistance Heating Materials.
Current edition approved Oct. 1, 2014Oct. 1, 2020. Published October 2014October 2020. Originally approved in 1959. Last previous edition approved in 20112014 as
B344B344 – 14. – 11. DOI: 10.1520/B0344-14.10.1520/B0344-20.
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’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 ----------------------
B344 − 20
4. Requirements
4.1 The alloys shall conform to the requirements as to chemical composition prescribed in Table 1.
4.2 Samples for Chemical Analysis—Specimens for chemical analysis may be taken from either the melt or from a sample of
finished wire that is representative of the lot.
4.2.1 The lot size for determining compliance with the requirements of this specification shall be one heat.
4.3 Chemical Analysis—The chemical analysis shall be made in accordance with Test Methods A751, or by other analytical
methods approved by the purchaser.
4.4 Actual chemical analysis is not required for routine acceptance.
5. Physical Requirements
5.1 The material shall be thoroughly and uniformly annealed.
5.2 Wire shall conform to the following elongation requirements:
Size Elongation in 10 in.,
min, %
0.0035 in. (0.0889 mm) (No. 39 Awg) and larger 20
0.0031 in. (0.0787 mm) to 0.002 in. 10
(0.0508 mm) (Nos. 40 to 44 Awg)
5.3 Determination is not required for routine acceptance.
6. Nominal Resistivity
6.1 The nominal resistivity (Note 1) shall be the resi
...