ASTM A931-96(2002)
(Test Method)Standard Test Method for Tension Testing of Wire Ropes and Strand
Standard Test Method for Tension Testing of Wire Ropes and Strand
SIGNIFICANCE AND USE
Wire rope tests are generally to be performed on new rope. The use of wire rope in any application can reduce individual wire strengths due to abrasion and nicking that will result in the wire rope strength being reduced. Damage to the outer wires will also lower the maximum strength achieved during tension testing.
The modulus of elasticity of wire rope is not considered to be a standard requirement at this time. The determination of this material property requires specialized equipment and techniques.
Rope to be tested should be thoroughly examined to verify that no external wire damage is present. If present, it should be noted. When possible, a new undamaged sample should be obtained for testing.
End attachments and their installation can directly affect breaking strength achieved during testing. Any attachment that can be used to directly achieve the required rope breaking strength can be used. Standard testing with a poured socket, using zinc, white metal or thermoset resin, has been considered the most efficient. Proficiency in attachment of any fitting can have a direct effect on the final test results.
SCOPE
1.1 This test method covers the tension testing of wire ropes and strand at room temperature, specifically to determine the minimum acceptance strength or nominal strength, yield strength, elongation, and modulus of elasticity.
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
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. Specific precautionary statements are given in Note 1, Note 2, Note 3, and Note 5.
General Information
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Standards Content (Sample)
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Designation:A 931–96 (Reapproved 2002)
Standard Test Method for
Tension Testing of Wire Ropes and Strand
This standard is issued under the fixed designation A 931; 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 3.2.1 abrasion—frictional surface wear on the wires of a
wire rope.
1.1 This test method covers the tension testing of wire ropes
3.2.2 aggregate area—see area, metallic.
and strand at room temperature, specifically to determine the
3.2.3 aggregate strength—the strength derived by totalling
minimum acceptance strength or nominal strength, yield
the individual breaking strengths of the elements of the strand
strength, elongation, and modulus of elasticity.
or rope. This strength does not give recognition to the
1.2 The values stated in inch-pound units are to be regarded
reduction in strength resulting from the angularity of the
as the standard. The SI units given in parentheses are for
elements in the rope, or other factors that may affect efficiency.
information only.
3.2.4 area, metallic—sum of the cross-sectional areas of all
1.3 This standard does not purport to address all of the
wires either in a wire rope or in a strand.
safety concerns, if any, associated with its use. It is the
3.2.5 breaking strength—theultimateloadatwhichatensile
responsibility of the user of this standard to establish appro-
failure occurs in the sample of wire rope being tested.
priate safety and health practices and determine the applica-
3.2.6 Discussion—The term breaking strength is synony-
bility of regulatory limitations prior to use. Specific precau-
mous with actual strength.
tionary statements are given in Note 1, Note 2, Note 3, and
3.2.7 cable—a term loosely applied to wire rope, wire
Note 5.
strand, and electrical conductors.
2. Referenced Documents
3.2.8 center—the axial member of a strand about which the
wires are laid.
2.1 ASTM Standards:
3.2.9 classification—group or family designation based on
A 586 Specification for Zinc-Coated Parallel and Helical
wire rope constructions with common strengths and weights
Steel Wire Structural Strand and Zinc-Coated Wire for
listed under the broad designation.
Spun-In-Place Structural Strand
3.2.10 construction—geometric design description of the
A 603 Specification for Zinc-Coated Steel Structural Wire
wire rope’s cross section. This includes the number of strands,
Rope
the number of wires per strand, and the pattern of wire
B 6 Specification for Zinc
arrangement in each strand.
E 4 Practices for Force Verification of Test Machines
3.2.11 core—the axial member of a wire rope about which
E 6 Terminology Relating to Methods of Mechanical Test-
the strands are laid.
ing
3.2.12 fiber core—cord or rope of vegetable or synthetic
E 8 Test Methods forTensionTesting of Metallic Materials
fiber used as the core of a rope.
3. Terminology
3.2.13 galvanized rope—wire rope made up of galvanized
wire.
3.1 The terminology relating to tensile testing in Terminol-
3.2.14 galvanized strand—strand made up of galvanized
ogy E 6 applies to this test method. In addition, the following
wire.
definitions for wire rope will apply:
3.2.15 grade—wire rope or strand classification by strength
3.2 Definitions:
or type of material, that is, Class 3, Type 302 stainless,
phosphor bronze, etc. It does not apply to strength of the
This test method is under the jurisdiction of ASTM Committee A01 on Steel,
individual wires used to manufacture the rope or strand.
Stainless Steel, and RelatedAlloys and is the direct responsibility of Subcommittee
3.2.16 independent wire rope core (IWRC)—a wire rope
A01.03 on Steel Rod and Wire.
used as the core of a larger wire rope.
Current edition approved March 10, 1996. Published May 1996. Originally
published as A 931 – 94. Last previous edition A 931 – 94. 3.2.17 inner wires—all wires of a strand except the outer or
Annual Book of ASTM Standards, Vol 01.06.
cover wires.
Annual Book of ASTM Standards, Vol 02.04.
Annual Book of ASTM Standards, Vol 03.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 931–96 (2002)
3.2.18 lay—(a) the manner in which the wires in a strand or 5.3 The length of test specimen shall not be less than 3 ft,
the strands in a rope are helically laid, or (b) the distance (0.91 m) between sockets for wire ropes up to 1 in. (25.4 mm)
measured parallel to the axis of the rope (or strand) in which a diameter, inclusive, and not less than 5 ft (1.52 m) between
strand (or wire) makes one complete helical convolution about sockets for wire ropes 1 ⁄8 in. (28.6 mm) to 3 in. (77 mm)
the core (or center). In this connection, lay is also referred to as diameter. On wire ropes larger than 3 in. (77 mm), the clear
lay length or pitch. length of the test specimen shall be at least 20 times the rope
3.2.19 minimum acceptance strength—thatstrengththatis2 diameter.
1 2 % lower than the catalog or nominal strength. This
/
6. Apparatus
tolerance is used to offset variables that occur during sample
6.1 Testing Machines—Machines used for tension testing
preparation and actual physical test of a wire rope.
shall conform to the requirements of Practices E 4. The loads
3.2.20 modulus of elasticity—theslopeoftheelasticportion
used in determining tensile strength and yield strength shall be
of the stress-strain curve. The ratio of stress to corresponding
within loading range of the tensile machine as defined in
strain below the proportional limit. This value is generally
Practices E 4.
taken between 20 and 50 % of the nominal strength.
6.2 Gripping Devices:
3.2.21 nominal strength—the published (catalog) strength
calculated by a standard procedure that is accepted by the wire 6.2.1 General—Various types of gripping devices may be
used to transmit the measured load applied by the testing
rope industry.The wire rope manufacturer designs wire rope to
this strength, and the user should consider this strength when machine to test specimens.To ensure axial tensile stress within
the gage length, the axis of the test specimen should coincide
making design calculations.
3.2.22 socket—generic name for a type of wire rope fitting. with the center line of the heads of the machine.Any departure
from this requirement may introduce bending stresses that are
3.2.23 strand—a plurality of round or shaped wires heli-
cally laid about a center. not included in the usual stress computation.
6.2.2 Wedge Grips—Testing machines usually are equipped
3.2.24 wire rope—strands helically laid around a core.
with wedge grips. These wedge grips generally furnish a
3.2.25 wire strand core (WSC)—a wire strand used as the
satisfactorymeansofgrippinglongspecimensofductilemetal.
core of a wire rope.
If, however, for any reason, one grip of a pair advances farther
4. Significance and Use
than the other as the grips tighten, an undesirable bending
4.1 Wire rope tests are generally to be performed on new stress may be introduced. When liners are used behind the
rope. The use of wire rope in any application can reduce wedges, they must be of the same thickness and their faces
individual wire strengths due to abrasion and nicking that will must be flat and parallel. For best results, the wedges should be
result in the wire rope strength being reduced. Damage to the supported over their entire lengths by the heads of the testing
outer wires will also lower the maximum strength achieved machine. This requires that liners of several thicknesses be
during tension testing. available to cover the range of specimen thickness. For proper
4.2 The modulus of elasticity of wire rope is not considered gripping, it is desirable that the entire length of the serrated
to be a standard requirement at this time. The determination of face of each wedge be in contact with the specimen. Specially-
this material property requires specialized equipment and designed round-shaped grips may have to be used for testing
techniques. rope or strand. It is essential that all wires in the rope or strand
4.3 Rope to be tested should be thoroughly examined to are uniformly gripped when the load is applied.
verify that no external wire damage is present. If present, it 6.2.3 Conical Grips—Conical grips are constructed so that
should be noted. When possible, a new undamaged sample when they are fitted together, a conical-shaped cavity exists
should be obtained for testing. which will hold a cone socket wire rope or strand and
4.4 End attachments and their installation can directly affect attachment (fitting).
breaking strength achieved during testing.Any attachment that
7. Sample Preparation and Preparation of End
can be used to directly achieve the required rope breaking
Attachments
strength can be used. Standard testing with a poured socket,
7.1 Poured sockets are considered to be the most efficient
using zinc, white metal or thermoset resin, has been considered
and should be used due to their ability to distribute the load
the most efficient. Proficiency in attachment of any fitting can
evenly in the wire rope when installed properly. Procedures for
have a direct effect on the final test results.
the proper installation of poured end attachments can be found
5. Interferences
in socketing procedures.
5.1 Visual examination of the sample for any damage to 7.2 Other end attachments such as grips may be used
outer wires should be done. If any damage is evident, the provided the required loading is achieved.
sample should not be used. The purpose of this test method is 7.3 Sample Preparation Procedures:
to verify the nominal or maximum strength the wire rope or 7.3.1 Socketing
strand can achieve. Zinc-Poured Socketing:
5.2 Measurement of the rope or strand sample is necessary 7.3.1.1 Measuring the Rope Ends to be Socketed—The rope
to document the size, length between end attachments, and end should be of sufficient length so that the ends of the unlaid
length of lay of the rope if necessary. Further details regarding wires (from the s
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