ASTM B820-04

Standard Test Method for Bend Test for Determining the Formability of Copper and Copper Alloy Strip

SCOPE
1.1 This test method describes the technique of bend testing copper and copper alloy strip samples to determine product formability or the ability to resist cracking when forming a bend around a specific radius. The criterion for failure is the occurrence of cracks on the outer radius of curvature (convex).
1.2 This bend test is limited to strip from 0.003 to and including 0.031 in. thick. (0.076 to and including 0.79 mm).
1.3 The size of the forming radii used in this test shall be 0.005 to 0.250 in. (0.127 to and including 6.35 mm).
1.4 UnitsThe values stated in inch-pounds 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.
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-Apr-2004
• Technical Committee: B05 - Copper and Copper Alloys
• Drafting Committee: B05.06 - Methods of Test

Relations

• Replaces: ASTM B820-98 - Standard Test Method for Bend Test for Formability of Copper Alloy Spring Material
• Effective Date: 01-May-2004
• Replaced By: ASTM B820-04e1 - Standard Test Method for Bend Test for Determining the Formability of Copper and Copper Alloy Strip
• Effective Date: 01-May-2004
• Referred By: ASTM B888/B888M-19 - Standard Specification for Copper Alloy Strip for Use in Manufacture of Electrical Connectors or Spring Contacts
• Effective Date: 01-May-2004
• Referred By: ASTM B740-21 - Standard Specification for Copper-Nickel-Tin Spinodal Alloy Strip
• Effective Date: 01-May-2004
• Referred By: ASTM B194-22 - Standard Specification for Copper-Beryllium Alloy Plate, Sheet, Strip, and Rolled Bar
• Effective Date: 01-May-2004
• Referred By: ASTM B248-22 - Standard Specification for General Requirements for Wrought Copper and Copper-Alloy Plate, Sheet, Strip, and Rolled Bar
• Effective Date: 01-May-2004
• Referred By: ASTM B248M-22 - Standard Specification for General Requirements for Wrought Copper and Copper-Alloy Plate, Sheet, Strip, and Rolled Bar (Metric)
• Effective Date: 01-May-2004

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: B 820 – 04
Standard Test Method for
Bend Test for Determining the Formability of Copper and
1
Copper Alloy Strip
This standard is issued under the fixed designation B 820; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope* 3. Terminology
1.1 This test method describes the technique of bend testing 3.1 Definitions—For definitions of terms related to copper
copper and copper alloy strip samples to determine product and copper alloys, refer to Terminology B 846, and for
formability or the ability to resist cracking when forming a definitions of terms relating to mechanical testing, refer to
bend around a specific radius. The criterion for failure is the Terminology E 6.
occurrence of cracks on the outer radius of curvature (convex). 3.2 Description of Terms Specific to This Standard:
1.2 This bend test is limited to strip from 0.003 to and 3.2.1 bend, longitudinal (or good way bend)—a bend with
including 0.031 in. thick. (0.076 to and including 0.79 mm). an axis perpendicular to the direction of rolling, drawing or
1.3 The size of the forming radii used in this test shall be extrusion (see Fig. 1).
0.005 to 0.250 in. (0.127 to and including 6.35 mm). 3.2.2 bend, transverse (or bad way bend)—a bend with an
1.4 Units—The values stated in inch-pounds are to be axis on a plane parallel to the direction of rolling, drawing or
regarded as standard. The values given in parentheses are extrusion (see Fig. 1).
mathematical conversions to SI units that are provided for
NOTE 1—The usage of these two terms is consistent with Test Method
information only and are not considered standard.
E 290.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4. Summary of Test Method
responsibility of the user of this standard to establish appro-
4.1 The bend test is made by applying a force transversely
priate safety and health practices and determine the applica-
to the length of the specimen in the portion being bent, usually
bility of regulatory limitations prior to use.
at midlength. The 90° bending forces are applied through an
arrangement illustrated in Fig. 2, while 180° bending forces are
2. Referenced Documents
applied through an arrangement illustrated in Fig. 3. When
2.1 The following documents in the current issue of the
complete fracture does not occur, the convex surface of the
Book of Standards form a part of this specification to the extent
specimen is examined for cracks. In general, the test using a
referenced herein:
180° bend angle is a more severe test than the test using a 90°
2
2.2 ASTM Standards:
bend angle.
B 846 Terminology for Copper and Copper Alloys
5. Significance and Use
E 6 Terminology Relating to Methods of Mechanical Test-
ing
5.1 This bend test provides information as to the formability
E 290 Test Method for Semi-Guided Bend Test for Ductility
or the ability of copper and copper alloy strip to resist cracking
of Metallic Materials
when being formed.
5.2 This test method can be used as a quality control tool to
determine if material will form to a given radius.
1
This test method is under the jurisdiction of ASTM Committee B05 on Copper
5.3 This test method is also useful in research and develop-
and Copper Alloys and is the direct responsibility of Subcommittee B05.06 on
ment to provide data for use in selecting a spring material that
Methods of Test.
will safely form to the geometry of a given part.
Current edition approved May 1, 2004. Published May 2004. Originally
approved in 1992. Last previous edition approved in 1998 as B 820 – 98.
5.4 The results are suitable for direct application in design
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and manufacturing, only when all factors such as the geometry
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
of the part, punch and die design, lubrication, stamping speed,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. and other material properties are known.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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B 820–04
7.2 The test specimens may be prepared by cutting, shear-
ing, or stamping.
1 1
7.3 The test specimens shall have a width of ⁄2 6 ⁄16 in.
1
(12.7 6 1.57 mm) and of any convenient length greater than ⁄2
in. (12.7 mm) unless specified otherwise by purchaser.
7.4 Directio
...