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UDC 669.14: 620.17
IS0
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
IS0 RECOMMENDATION
R 85
BEND TEST FOR STEEL
1st EDITION
February 1959
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Copies to be obtained through the national standards organizations.
Also issued in French and Russian.
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BRIEF HISTORY
The IS0 Recommendation R 85, Bend Test for Steel, was drawn up by
Technical Committee ISO/TC 17, Steel, the Secretariat of which is held by the
British Standards Institution (B.S. I.).
At the first meeting of ISO/TC 17, held in London, in June 1950, the
Secretariat submitted a first draft proposal for the bend test, based on a docu-
ment which had been drawn up by the former International Federation of the
Vational Standardizing Associations (ISA). The Technical Committee instruc-
ted its Working Group No. 1, il!lefliods vf hlechanical Testing for Stecl, to examine
this draft proposal and to prepare a new version of it, taking into account certain
observations put forward by Member Bodies.
In April 1952, the Working Group submitted a second draft proposal,
which was discussed at the second plenary meeting of ISO/TC 17, held in New
York, in June 1952, and which was passed back io the Working Group so that
it might include therein data on tolerances.
The third draft proposal, submitted by the Working Group in August 1953,
was studied by the Technical Committee during its third plenary meeting, held
in London, in December 1953, along with the comments of the Member Bodies.
The ISO/TC 17 Secretariat was then assigned to draw up a fourth draft pro-
posal incorporating the changes voted during the meeting, and this was cir-
culated in April 1954.
The comments of the Member Bodies on this fourth draft proposal were
discussed at the fourth plenary meeting, held in Stockholm, in June 1955, and the
Technical Committee decided to adopt it, subject to a few amendments, as a
Draft IS0 Recommendation.
On 31 October 1956, this Draft IS0 Recommendation (No. 136) was dis-
tributed to all the IS0 Member Bodies and was approved, subject to a few
modifications of details, by the following Member Bodies :
Australia *Greece Spain
Belgium Hungary Sweden
*Canada *Ireland Turkey
Italy *Union of
Czechoslovakia
Japan South Africa
Denmark
Finland Netherlands U.S.S.R.
France Poland Yugoslavia
Germany Portugal
No Member Body opposed the approval of the Draft.
The Draft IS0 Recommendation was then submitted by correspondence
to the IS0 Council, which decided, in February 1959, to accept it as an
IS0 RECOMMENDATION.
These Member Bodies stated that they had no objection to the Draft being approved.
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ISO/R 85 - 1959 (E)
February 1959
R 85
IS0 Recommendation
BEND TEST FOR STEEL
I. SCOPE
For the bend testing of certain products such as sheets, strips, wires and tubes,
particular specifications are applicable.
2. PRINCIPLE OF TEST
Thv test consists in submitting to plastic deformation by bending a straight,
solid, prismatic- or round-section test piece without reversing the direction of
flexure during the test. The bending is carried out until one leg of the test
piece makes, under load, a specified angle a with the extension of the other
(see Fig. 2). The axes of the two legs of the test piece remain in a plane
perpendicular to the axis of bending. In the case of 180" bend, the two lateral
surfaces may, depending on the requirements of the specification, lie flat
against each other, or may be parallel at a specified distance; an intermediate
piece may be used for the control of this distance (see Fig. 4).
3. SYMBOLS AND DESIGNATIONS
Designation
Number Symbol
a Thickness or diameter of test piece
b Width of test piece
-
Distance between supports (see Fig. 1 and 2) or
the opening of a block, U-shaped or V-shaped
(see Fig. 3)
a Angle of bend
R Radius of supports
D Diameter of mandrel
-
Radius of curvature of pressure piece
r Internal radius of the bent portion of the test
piece after bending
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ISO/R85 - 1959 (E)
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FIG.
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