ASTM A721/A721M-02(2011)

Standard Test Method for Ductility of Oriented Electrical Steel

SIGNIFICANCE AND USE
This is a specialized bend test for grain-oriented steel not covered under the provisions of Test Methods E290.
This test is applicable to grain-oriented silicon steel such as covered in Specification A876 in commercial thicknesses and widths up to 36 in. [910 mm].
SCOPE
1.1 This test method covers determination of the ductility of grain-oriented silicon steel by use of an apparatus known variously as a tinner's brake, hand folder, or an apron brake.
1.2 The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard. Within this test method, 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 test method.
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 establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Sep-2011
• ICS: 77.140.50 - Flat steel products and semi-products
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.01 - Test Methods

Relations

• Replaces: ASTM A721/A721M-02(2007) - Standard Test Method for Ductility of Oriented Electrical Steel
• Effective Date: 01-Oct-2011
• Referred By: ASTM A876-17e1 - Standard Specification for Flat-Rolled, Grain-Oriented, Silicon-Iron, Electrical Steel, Fully Processed Types
• Effective Date: 01-Oct-2011
• Referred By: ASTM A345-19 - Standard Specification for Flat-Rolled Electrical Steels for Magnetic Applications
• Effective Date: 01-Oct-2011

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: A721/A721M − 02(Reapproved 2011)
Standard Test Method for
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Ductility of Oriented Electrical Steel
This standard is issued under the fixed designationA721/A721M; 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 4.2 Thistestisapplicabletograin-orientedsiliconsteelsuch
as covered in Specification A876 in commercial thicknesses
1.1 This test method covers determination of the ductility of
and widths up to 36 in. [910 mm].
grain-oriented silicon steel by use of an apparatus known
variously as a tinner’s brake, hand folder, or an apron brake.
5. Apparatus
1.2 The values and equations stated in customary (cgs-emu
5.1 The machine required to perform this test is known
and inch-pound) or SI units are to be regarded separately as
variously as a tinner’s brake, hand folder, or an apron brake.
standard. Within this test method, SI units are shown in
brackets. The values stated in each system may not be exact
5.2 The brake shall be at least 36 in. [910 mm] wide with an
equivalents; therefore, each system shall be used independently
opening capacity of approximately 0.035 in. [0.9 mm].
of the other. Combining values from the two systems may
5.2.1 The nose bar shall have a 0.031-in. [0.8-mm] radius.
result in nonconformance with this test method.
5.2.2 The bending bar must be movable through an angle of
1.3 This standard does not purport to address all of the
at least 160°.
safety concerns, if any, associated with its use. It is the
5.2.3 The movable table or apron shall move around the end
responsibility of the user of this standard to establish appro-
of the nose bar at a distance of approximately 0.25 in. [6.35
priate safety and health practices and determine the applica-
mm].
bility of regulatory limitations prior to use.
6. Test Specimen
2. Referenced Documents
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6.1 Two specimens are required and they shall be selected
2.1 ASTM Standards:
from the same general location as that of the magnetic test
A34/A34M Practice for Sampling and Procurement Testing
specimens in accordance with Practice A34/A34M.
of Magnetic Materials
A876 Specification for Flat-Rolled, Grain-Oriented, Silicon-
6.2 The specimens shall be cut transversely to the rolling
Iron, Electrical Steel, Fully Processed Types
direction and have a length equal to the sheet or strip width and
E290 Test Methods for Bend Testing of Material for Ductil-
a minimum dimension of 3 in. [80 mm] in the direction of
ity
rolling.
3. Summary of Test Method
6.3 The specimens shall be free of rust, ripples, and
scratches.
3.1 A test specimen representing the full width of grain-
oriented steel to be tested is bent through an angle of about
7. Procedure
160° in a tinner’s brake. The number of breaks, or fractures,
occurring along the bend determines the ductility class rating.
7.1 The test specimen shall be at a temperature of 25 6 5°C
at the start of the test.
4. Significance and Use
7.2 Insert the test specimen into the brake and clamp with
4.1 This is a specialized bend test for grain-oriented steel
the direction of rolling perpendicular to the nose bar and 0.5 to
not covered under the provisions of Test Methods E290.
1.5 in. [12 to 40 mm] under the nose bar thereby allowing the
1 balance of the specimen width to rest against the bending bar.
This test method is under the jurisdiction of ASTM Committee A06 on
Magnetic Properties and is the direct responsibility of Subcommittee A06.01 on Test
7.3 Bend the specimen around the nose bar at a uniform rate
Methods.
by rotating the bending bar through an angle of 160°.
Current edition approved Oct. 1, 2011. Published October 2011. Originally
approved in 1975. Last previous edition approved in 2007 as A721/
7.4 Remove the specimen from the machine and without
A721M – 02(2007). DOI: 10.1520/A0721_A0721M-02R11.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or straighteningthebend,examinetheoutsidefaceofthebendfor
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
surface breaks, without magnification.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 7.5 Count the breaks and measure for length.
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A721/A721M − 02 (2011)
8. Interpretation of Results 8.3 When the evaluating steel narrower than 24 in. [610
mm], the number of breaks should be multiplied by the ratio of
8.1 Classify each test specimen according to length of
24 over the strip width
...