ASTM A726-18 - 1.10.2018
 
1. Scope

1.1 This specification covers cold-rolled carbon sheet steel used for magnetic applications. These products, commonly called “cold-rolled magnetic lamination steel” (CRML) are usually intended for applications in which the stamped laminations or assembled core structures for electrical equipment are annealed to develop the desired core loss and permeability characteristics.

1.2 This steel is produced to maximum specific core-loss values and is intended primarily for commercial power frequency (50- and 60-Hz) applications in magnetic devices. Specific core-loss and permeability characteristics in conformance with this specification are developed through heat treatment by the user.

1.3 Non-guaranteed core-loss types, usually made to controlled chemical compositions, are available but are not covered by this specification.

1.4 Higher quality core-loss types are low carbon, silicon-iron, or silicon-aluminum-iron alloys containing up to about 2.5 % silicon and less than 1 % aluminum. These steels are usually given a critical reduction on a temper-mill to yield specified magnetic properties after a suitable lamination anneal. These products, typically called semiprocessed magnetic lamination steel, are classified by the ASTM Code Letter D in accordance with Practice A664.

1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to customary (cgs-emu and inch-pound) units which are provided for information only and are not considered standard.

1.6 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 establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 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

E140-12B(2019)e1

Standard Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb Hardness (Includes all amendments and changes 5/7/2019).

E18-22

Standard Test Methods for Rockwell Hardness of Metallic Materials

A700-14(2019)

Standard Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment

A664-15(2022)

Standard Practice for Identification of Standard Electrical Steel Grades in ASTM Specifications

A370-23

Standard Test Methods and Definitions for Mechanical Testing of Steel Products

A343/A343M-14(2019)

Standard Test Method for Alternating-Current Magnetic Properties of Materials at Power Frequencies Using Wattmeter-Ammeter-Voltmeter Method and 25-cm Epstein Test Frame

A340-23a

Standard Terminology of Symbols and Definitions Relating to Magnetic Testing (Includes all amendments and changes 12/19/2023).