ASTM B344-20 PDF

Full title and description

Standard Specification for Drawn or Rolled Nickel‑Chromium and Nickel‑Chromium‑Iron Alloys for Electrical Heating Elements — specification that defines chemical compositions, permitted product forms, and general requirements for nickel‑chromium (nichrome) and nickel‑chromium‑iron resistance‑heating alloys supplied as drawn or rolled shapes for electrical heating applications.

Abstract

This brief specification covers annealed, drawn, or rolled shapes intended for electrical heating purposes made from several nominal nickel‑chromium and nickel‑chromium‑iron alloy compositions (including typical 80Ni‑20Cr and other Ni‑Cr‑Fe variants). It specifies units (inch‑pound as standard, SI conversions for information), references related test methods, and notes user responsibility for applicable safety data and regulatory compliance.

General information

• Status: Active — reaffirmed (document available as B344‑20 and shown with a 2025 reaffirmation entry).
• Publication date: 2020 (published September/October 2020).
• Publisher: ASTM International (formerly ASTM Committee B02, Subcommittee B02.10).
• ICS / categories: 77.150.40 (Nickel and chromium products).
• Edition / version: B344‑20 (with a reaffirmation notation B344‑20R25 shown in the ASTM record).
• Number of pages: 4 pages.

Scope

This specification covers annealed, drawn, or rolled shapes for electrical heating purposes of alloys having the nominal compositions such as 80% Ni ‑ 20% Cr and multiple Ni‑Cr‑Fe combinations (for example 60% Ni‑16% Cr+Fe remainder, 35% Ni‑20% Cr+Fe remainder, 38% Ni‑21% Cr+Fe remainder, etc.). Inch‑pound units are the standard; SI conversions are provided for information only. The standard also reminds users to consult Safety Data Sheets and applicable regulations when using these materials.

Key topics and requirements

• Defined nominal alloy compositions for Ni‑Cr and Ni‑Cr‑Fe resistance‑heating alloys (including the common 80/20 Ni‑Cr composition).
• Permitted product forms: annealed, drawn (wire), or rolled shapes (including flat wire and strip used as heating elements).
• Units and measurement conventions: inch‑pound units are primary; SI conversions provided for information.
• Referenced test methods and practices for resistivity, change of resistance with temperature, accelerated life testing, and chemical analysis are invoked as appropriate.
• Responsibility statement for user safety practices and applicable regulatory/SDS compliance when handling alloy products.

Typical use and users

Manufacturers of electric heating elements and resistance wire, wire and strip producers, metallurgical and materials engineers, quality assurance and inspection labs, and designers of heating equipment (industrial furnaces, small appliance heaters, toasters, and other resistive heating devices) commonly use this specification to procure and verify compliant nichrome and related heating alloys.

Related standards

Standards commonly referenced or relevant include ASTM test methods and practices such as B63 (resistivity), B70 (change of resistance with temperature), B76 (accelerated life of Ni‑Cr alloys), A751 (chemical analysis practices), and related material specifications such as ASTM B603 (iron‑chromium‑aluminum heating alloys). This specification supersedes/updates earlier editions of B344 (for example B344‑14 as the prior edition).

Keywords

nickel‑chromium, Ni‑Cr, nichrome, nickel‑chromium‑iron, resistance alloy, heating element wire, flat wire, drawn wire, rolled strip, electrical heating, B344, ASTM B344‑20.

FAQ

Q: What is this standard?

A: ASTM B344‑20 is a short ASTM specification that defines acceptable compositions, forms, and general requirements for drawn or rolled nickel‑chromium and nickel‑chromium‑iron alloys used as electrical heating elements.

Q: What does it cover?

A: It covers annealed, drawn, or rolled shapes for electrical heating purposes and lists the nominal alloy compositions, unit conventions (inch‑pound standard), and references to related test methods and safety considerations.

Q: Who typically uses it?

A: Manufacturers and suppliers of resistance heating wire/strip, materials and process engineers, product designers of heating devices, and quality/inspection personnel use the standard to specify or verify heating‑alloy materials.

Q: Is it current or superseded?

A: The B344‑20 edition was published in 2020 (September/October 2020) and is shown in ASTM records with a 2025 reaffirmation entry (B344‑20R25), indicating the 2020 edition remains the active document in ASTM's catalog. Some commercial cataloging entries may list historical cancellation or replacement of older editions (for example B344‑14 was the prior edition).

Q: Is it part of a series?

A: It is part of ASTM Committee B02 (Nonferrous Metals and Alloys) publications and is grouped with other ASTM specifications and test methods that address resistance heating materials (for example ASTM B603, B70, B76, etc.).

Q: What are the key keywords?

A: nickel‑chromium, nichrome, nickel‑chromium‑iron, resistance alloy, heating element, drawn wire, rolled strip, flat wire, ASTM B344‑20.