ASTM-A971 Historical Revision Information
Standard Test Method for Measuring Edge Taper and Crown of Flat-Rolled Electrical Steel Coils

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Standard Test Method for Measuring Edge Taper and Crown of Flat-Rolled Electrical Steel Coils


1.1 This test method provides a procedure for measuring edge taper and crown of flat-rolled electrical steel coils as produced at the steel mill.

1.2 The values and equations stated in customary (cgs-emu and inch-pound) units or SI units are to be regarded separately as standard. Within this standard, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this standard.

1.3 The following material specifications include requirements for edge taper or crown: A677, A683, A726, A840, and A876.

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

Significance and Use

Flat-rolled electrical steel master coils are usually slit into narrower coils. Usually these slit coils are punched or sheared into laminations of various shapes. The laminations are then uniformly stacked to become the cores of magnetic devices such as motors and transformers. Stacking of many laminations exhibiting excessive taper causes assembly problems and poor appearance. Nonuniform stack lengths in motors cause imbalance and noise. When the laminations are interleaved in transformers, taper causes air spaces within the core resulting in increased noise, increased exciting current, and higher core loss.


coupon; crown; edge taper; edge trim; gamma strip; master coil; slit coil; Crown; Edge taper; Electrical steel; Flat-rolled electrical steel; Gamma strip; Master coil; Slit coil; ICS Number Code 77.140.50 (Flat steel products and semi-products)

To find similar documents by ASTM Volume:

03.04 (Magnetic Properties)

To find similar documents by classification:

77.140.50 (Flat steel products and semi-products Including plate, sheet and strip Steel strips for springs, see 77.140.25)

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Document Number


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Modification Type


Publication Date

Nov. 1, 2010

Document Type

Test Method

Page Count

4 pages

Committee Number