ASTM D4975-04(2011)
(Test Method)Standard Test Methods for Single-Filament Tire Bead Wire Made from Steel
Standard Test Methods for Single-Filament Tire Bead Wire Made from Steel
SIGNIFICANCE AND USE
The procedures for the determination of properties of single-filament bead wire made from steel are considered satisfactory for acceptance testing of commercial shipments of this product because the procedures are the best available and have been used extensively in the trade.
In case of a dispute arising from differences in reported test results when using these test methods for acceptance testing of commercial shipments, the purchaser and supplier should conduct comparative test to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens which are as homogeneous as possible and which are from a lot of material of the type in question. The test specimens then should be randomly assigned in equal number to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be determined and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.
SCOPE
1.1 These test methods cover testing of single-filament steel wires that are components of tire beads used in the manufacture of pneumatic tires. By agreement, these test methods may be applied to similar filaments used for reinforcing other rubber products.
1.2 These test methods describe test procedures only and do not establish specifications and tolerances.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
General Information
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D4975 − 04(Reapproved 2011)
Standard Test Methods for
Single-Filament Tire Bead Wire Made from Steel
This standard is issued under the fixed designation D4975; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 Thesetestmethodscovertestingofsingle-filamentsteel
3.1 Definitions:
wiresthatarecomponentsoftirebeadsusedinthemanufacture
3.1.1 Fordefinitionsoftermsrelatingtotirecord,beadwire,
of pneumatic tires. By agreement, these test methods may be
hose wire, and tire cord fabrics, refer to Terminology D6477.
applied to similar filaments used for reinforcing other rubber
3.1.1.1 The following terms are relevant to this standard:
products.
percent elongation, tire bead, tire bead wire, torsion resistance,
1.2 Thesetestmethodsdescribetestproceduresonlyanddo in tire bead wire, yield strength.
not establish specifications and tolerances.
3.1.2 For definitions of terms related to force and deforma-
tion in textiles, refer to Terminology D4848
1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this 3.1.2.1 The following terms are relevant to this standard:
breaking force.
standard.
3.1.3 For definitions of other textile terms, refer to Termi-
1.4 These test methods cover the determination of the
nology D123.
mechanical properties listed below:
Property Section
4. Summary of Test Methods
Breaking Force (Strength) 7–13
4.1 A summary of the procedures prescribed for the deter-
Yield Strength 7–13
Elongation 7–13
mination of specific properties of tire bead wire is stated in the
Torsion Resistance 14–20
appropriate sections of the specific test methods that follow.
Diameter (Gage) 21–27
1.5 This standard does not purport to address all of the
5. Significance and Use
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5.1 The procedures for the determination of properties of
priate safety and health practices and determine the applica- single-filament bead wire made from steel are considered
bility of regulatory limitations prior to use.
satisfactory for acceptance testing of commercial shipments of
this product because the procedures are the best available and
2. Referenced Documents
have been used extensively in the trade.
2.1 ASTM Standards: 5.1.1 In case of a dispute arising from differences in
reported test results when using these test methods for accep-
D76Specification for Tensile Testing Machines for Textiles
tance testing of commercial shipments, the purchaser and
D123Terminology Relating to Textiles
supplier should conduct comparative test to determine if there
D4848Terminology Related to Force, Deformation and
is a statistical bias between their laboratories. Competent
Related Properties of Textiles
statistical assistance is recommended for the investigation of
D6477TerminologyRelatingtoTireCord,BeadWire,Hose
bias.Asaminimum,thetwopartiesshouldtakeagroupoftest
Reinforcing Wire, and Fabrics
specimens which are as homogeneous as possible and which
are from a lot of material of the type in question. The test
These test methods are under the jurisdiction of ASTM Committee D13 on
specimens then should be randomly assigned in equal number
Textiles and are the direct responsibility of Subcommittee D13.19 on Industrial
toeachlaboratoryfortesting.Theaverageresultsfromthetwo
Fibers and Metallic Reinforcements.
laboratories should be compared using Student’s t-test for
Current edition approved Jan. 1, 2011. Published March 2011. Originally
unpaireddataandanacceptableprobabilitylevelchosenbythe
approved in 1989. Last previous edition approved in 2010 as D4975–04(2010).
DOI: 10.1520/D4975-04R11.
two parties before testing is begun. If a bias is found, either its
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cause must be determined and corrected or the purchaser and
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
the supplier must agree to interpret future test results with
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. consideration to the known bias.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
D4975 − 04 (2011)
6. Sampling the various possibilities for recording test data, use of this type
of equipment is not covered in this test method.
6.1 Lot Sample—Asalotsampleforacceptancetesting,take
at random the number of reels, coils, spools, or other shipping 9.3 Grips, of such design that failure of the specimen does
units of wire directed in an applicable material specification or not occur at the gripping point, and slippage of the specimen
other agreement between the purchaser and the supplier. within the jaws (grips) is prevented.
Consider reels, coils, spools, or other shipping units of wire to
be the primary sampling units. 10. Procedure
10.1 Thermally age the specimen by placing it in an oven
NOTE 1—A realistic specification or other agreement between the
purchaser and the supplier requires taking into account the variability
for 60 6 1 min, at 150 6 3°C. Allow specimens to cool to
between and within primary sampling units so as to provide a sampling
room temperature before testing.
plan which at the specified level of the property of interest has a
10.2 Select the proper force scale range on the tensile
meaningfulproducer’srisk,consumer’srisk,acceptablequalitylevel,and
desired limiting quality level.
testing machine based on the estimated breaking force of the
specimen being tested.
6.2 Laboratory Sample—Use the primary sampling units in
the lot sample as a laboratory sample.
10.3 Adjust the distance between the grips of the testing
machine, nip to nip, to a gage length of 250 mm.
6.3 Test Specimens—For each test procedure, take the num-
ber of lengths of tire bead wire of the specified lengths from
10.4 Secure the specimen in the top clamp, exerting enough
each laboratory sample as directed in the test procedure.
pressure to prevent the specimen from slipping when loaded.
Place the other end of the specimen between the jaws of the
BREAKING FORCE, YIELD STRENGTH, AND
bottom clamp.
ELONGATION
10.5 Apply a pretension of 1% of full scale to keep the
specimen taut.
7. Summary of Test Method
10.6 After setting the cross head speed at 25 mm/min and
7.1 The two ends of a specimen are clamped in a tensile
recorder chart speed at 250 mm/min, start the testing machine
testing machine; an increasing force is applied until the
and record the force-extension curve generated.
specimen breaks. The change in force is measured versus the
10.6.1 Ifthespecimenfractureswithin5mmofthegripping
increase in separation of the specimen clamps to form a
point, discard the result and test another specimen. If such jaw
force-extension curve. Breaking force is read directly from the
breaks continue to occur, insert a jaw liner such as an abrasive
curve and is expressed in newtons. Percent elongation at break
cloth between the gripping surface and the specimen in a
is the extension at break divided by the original specimen
manner so that the liner extends beyond the grip edge where it
length,×100. The yield strength, the intersection of the force-
comes in contact with the specimen.
extension curve with a line at 0.2% elongation offset, is read
from the force-extension curve and is expressed in newtons.
10.7 Conduct this test procedure on two specimens from
each laboratory sampling unit.
8. Significance and Use
10.8 Elongation, the increase in gage length of a tensile
8.1 The load-bearing ability of a reinforced rubber product
specimen, is usually expressed as a percentage of the original
such as a tire bead is related to the strength of the single-
gage length and can be determined from the force-extension
filament wire used as the reinforcing material. The breaking
curve.
forceandyieldstrengthoftirebeadwireisusedinengineering
10.8.1 When a greater degree of accuracy is required in the
calculations when designing this type of reinforced product.
determination of elongation, an extensometer can be attached
to the specimen.
8.2 Elongation of tire bead wire is taken into consideration
inthedesignandengineeringoftirebeadsbecauseofitseffect
10.9 Yield strength is the stress at which a material exhibits
on uniformity and dimensional stability during service.
a specified limiting deviation from the proportionality of stress
to strain. Determine the yield strength by the 0.2% offset
9. Apparatus
elongation method.
9.1 Tensile Testing Machine, CRE (Constant-Rate-of- 10.9.1 On the force-extension curve (Fig. 1) that has been
Extension) tensile testing machine of such capacity that the generated (see 10.6) mark off Om equal to the specified value
maximum force required to fracture the wire shall not exceed of the offset (0.2% elongation); draw mn parallel to OA and
90% nor be of less than 10% of the selected force measure- locate r.Thisintersectionof mnwiththeforce-extensioncurve
ment range. The specifications and methods of calibration and corresponds to force R which is the yield strength. Should the
verification for tensile testing machines shall conform to force-extension curve exhibit an initial nonlinear portion,
Specification D76. extrapolate from the straight line portion to the base line. The
intersection is point O used in this section.
9.2 In some laboratories, the output of CRE type of tensile
testing machine is connected with electronic recording and
11. Calculation
computing equipment which may be programmed to calculate
and print the results for each of these desired properties. 11.1 Calculate the average breaking force of the laboratory
Because of the variety of electronic equipment available and sample to the nearest 5 N.
D4975 − 04 (2011)
13.2 Precision—For the property of interest, two averages
of observed values should be considered significantly different
atthe95%probabilitylevelifthedifferenceequalsorexceeds
the critical differences given in Table 1.
NOTE 3—The tabulated values of the critical differences should be
considered to be a general statement, particularly with respect to between
laboratory precision. Before a meaningful statement can be made con-
cerninganytwospecificlaboratories,theamountofstatisticalbias,ifany,
between them must be established, with each comparison being based on
recent data obtained on specimens taken from a lot of material of the type
being evaluated so as to be as nearly homogeneous as possible and then
assigned randomly in equal numbers to each of the laboratories.
13.3 Bias—The procedures in this test method for measur-
ing breaking force, elongation, and yield strength have no
known bias because the value of these properties can be
defined only in terms of a test method.
TORSION RESISTANCE
14. Summary of Test Method
FIG. 1 Force-Extension Curve for Determination of Yield
Strength by the Offset Method
14.1 A single-filament of wire is tested in torsion by either
holdingoneendofthewirefixedwhilerotatingtheotherorby
rotating both ends in opposite directions at the same time until
11.2 Calculate the elongation to break from the force-
fracture occurs.
extension curve to the nearest 0.1%. Should the force-
extensioncurveexhibitaninitialnonlinearportion,extrapolate
15. Significance and Use
fromthestraightlineportionofthecurvetothebaseline.This
15.1 Complex stress and strain conditions, sensitive to
intersection is the point of origin for the elongation determi-
variationsinmaterials,occurinawirespecimenduringtorsion
nation. The extension from this point to the force at the point
testing. The torsion test is a useful tool in assessing wire
of break is the total elongation.
ductilityundertorsionalloading.Defectivewirelowerstorsion
11.3 Calculate the average yield strength of each laboratory
resistance.
sample as directed in 10.9.1 to the nearest 5 N.
16. Apparatus
12. Report
16.1 Torsion Test Machine, an automated drive apparatus
12.1 State that the tests were performed as directed in Test
that allows a single-filament wire under light tension to be
Methods D4975, describe the material or product tested, and
tested in torsion. A counter is provided that registers the
report the following:
number of wire rotations to wire fracture.
12.1.1 The test results of each specimen and the laboratory
sample average. Calculate and report any other data agreed to
17. Procedure
between the purchaser and the supplier,
17.1 Thermally age the specimen by placing it in a suitable
12.1.2 Date of test,
oven for 60 6 1 min. at 150 6 3°C.Allow specimens to cool
12.1.3 Type of tensile test machine and rate of extension,
to room temperature before testing.
and
12.1.4 Any deviation from the standard test procedure. 17.2 Cut the test specimen to the appropriate length so that
a gage length of 200 mm between chuck or jaw edges is
13. Precision and Bias
obtained.
13.1 Interlaboratory Test Data—Aninterlaboratorytestwas
17.3 Certain test equipment requires that a 90° bend be put
run in 1990 in which randomly drawn samples of four
in each end of the test specimen; if that is required, measure
materials were tested in 13 laboratories. Each laboratory used
approximately 25 mm from each end and bend the wire 90°
two operators, each of whom tested two specimens of each
with both bends in the same direction.
material on two separate days.
17.4 Placethespecimenintheclampingfixturesandtighten
NOTE 2—The bead wire products used in the interlaboratory evaluation the jaws while keeping the wire in a straight alignment. A
were of the following diameter and strength levels:
pretension 25 6 5 N shall be applied to the specimen in the
TABLE
longitudinaldirectiontoaidinkeepingthewirestraightduring
Material Diameter Strength
testing.
1 0.965 mm regular
17.5 Set the rotation counter to zero.
2 0.965 mm high
3 1.295 mm regular 17.6 Start the equipment and run until the specimen frac-
4 1.295 mm high
tures.Forwiresizesbelow1.40mm,usearotationspeedof60
D4975 − 04 (2011)
TABLE 1 Critical Differences for Conditions Noted
Number of Within-Laboratory
Name of Property Single Operator Precision Between-Laboratory Precision
Observations Precision
Single-Material Comparisons
Breaking force, N 1 17 17 27
21212 25
499 23
866 22
1644 22
Multi-Material Comparisons
11717 31
21212 28
499 27
866 26
1655 26
Single-Material Comparisons
A B
Yield strength, N Group 1 Group 2 Group 1 Gro
...
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