ASTM D2061-07(2021)

Standard Test Methods for Strength Tests for Zippers

SIGNIFICANCE AND USE
4.1 The usefulness of a zipper in service can be evaluated by these tests. No one test determines the suitability of a zipper for a specific end use. Since the tests are inter-related more than one may be needed for a complete evaluation.  
4.2 These methods are considered satisfactory for acceptance testing of commercial shipments because the methods have been used extensively in the trade for this purpose, and because estimates of current between-laboratory precision are acceptable in most cases.  
4.2.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative test should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, the test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results were obtained, and that are randomly assigned in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.  
4.3 The method(s) in the standard along with those in Test Methods D2051, D2052, D2053, D2054, D2057, D2058, D2059/D2059M, D2060, and D2062 are a collection of proven test methods. They can be used as aids in the evaluation of zippers without the need for a thorough knowledge of zippers. The enumerated test methods do not provide for the evaluation of all zipper properties. Besides those properties measured by means of the enumerated test methods there are other properties that may be important for the satisfactory performance of a zipper. Test methods for measuring those properties have not been ...
SCOPE
1.1 These test methods cover the determination of the strengths for zipper and zipper parts. All methods are not suitable for use with all kinds of zipper. The restrictions, if any, are indicated in the scope for each individual test method. The test methods appear as follows:    
Sections  
Holding Strengths of Separable Units  
25 – 32  
Holding Strength of Slider Lock  
92 – 100  
Holding Strength of Stops  
17 – 24  
Resistance to Angular Pull-Off of Slider Pull  
82 – 91  
Resistance to Cushioned Compression of Sliders  
33 – 42  
Resistance to Pull-Off of Slider Pull  
72 – 81  
Resistance to Twist of Pull and Slider  
52 – 61  
Slider Deflection and Recovery  
43 – 51  
Strength of Chains and Elements  
9 – 16  
Torsional Resistance of Slider Pull for Removal of Components  
62 – 71  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Jun-2021
• ICS: 61.040 - Headgear. Clothing accessories. Fastening of clothing
• Technical Committee: D13 - Textiles
• Drafting Committee: D13.54 - Subassemblies

Relations

• Refers: ASTM D1776/D1776M-20 - Standard Practice for Conditioning and Testing Textiles
• Effective Date: 01-Feb-2020
• Refers: ASTM D123-17 - Standard Terminology Relating to Textiles
• Effective Date: 01-Mar-2017
• Refers: ASTM D1776/D1776M-16 - Standard Practice for Conditioning and Testing Textiles
• Effective Date: 01-Jan-2016
• Refers: ASTM D123-15b - Standard Terminology Relating to Textiles
• Effective Date: 15-Sep-2015
• Refers: ASTM D123-15a - Standard Terminology Relating to Textiles
• Effective Date: 01-Sep-2015
• Refers: ASTM D123-15 - Standard Terminology Relating to Textiles
• Effective Date: 01-Apr-2015
• Refers: ASTM D1776/D1776M-15 - Standard Practice for Conditioning and Testing Textiles
• Effective Date: 01-Feb-2015
• Refers: ASTM D2060-14 - Standard Test Methods for Measuring Zipper Dimensions
• Effective Date: 01-Feb-2014
• Refers: ASTM D123-13ae1 - Standard Terminology Relating to Textiles
• Effective Date: 15-Jun-2013
• Refers: ASTM D123-13a - Standard Terminology Relating to Textiles
• Effective Date: 15-Jun-2013
• Refers: ASTM D123-13 - Standard Terminology Relating to Textiles
• Effective Date: 15-May-2013
• Refers: ASTM D123-12 - Standard Terminology Relating to Textiles
• Effective Date: 01-Feb-2012
• Refers: ASTM D123-12e1 - Standard Terminology Relating to Textiles
• Effective Date: 01-Feb-2012
• Refers: ASTM D76/D76M-11 - Standard Specification for Tensile Testing Machines for Textiles
• Effective Date: 01-Dec-2011
• Refers: ASTM D2050-11 - Standard Terminology Relating to Fasteners and Closures Used with Textiles
• Effective Date: 01-Jan-2011

Overview

ASTM D2061-07(2021), Standard Test Methods for Strength Tests for Zippers, is an internationally recognized standard that specifies methods for evaluating the strength performance of zippers and their components. Published by ASTM International, this standard details a suite of mechanical tests essential for determining the suitability of zippers across a broad range of textile products. Widely used in acceptance testing and quality control, ASTM D2061 helps ensure reliable zipper performance for both manufacturers and buyers.

Key Topics

• Test Scope
  ASTM D2061 includes tests for the strength of zippers and individual zipper parts. While not all methods are suitable for every zipper type, restrictions and applicability are clearly noted within each specific test method.

• Mechanical Strength Tests
  The standard encompasses procedures for:

  • Holding strengths (separable units, slider locks, stops)
  • Resistance to pull-off, twist, and compression (sliders and pulls)
  • Strength of zipper chains and elements
  • Slider deflection and recovery

• Statistical Precision
  Detailed instructions guide users to assess inter- and intra-laboratory test variability. When differences appear between laboratories, comparative testing and statistical analysis are encouraged to maintain accuracy and address potential bias.

• Acceptance Testing
  ASTM D2061 methods are validated for use in commercial shipment acceptance and have extensive use in trade, making them trusted for quality assurance processes.

Applications

• Quality Control in Manufacturing
  Zipper manufacturers and textile product assemblers leverage ASTM D2061 to verify zipper performance under realistic usage stresses. Using these test methods allows for identifying weaknesses in zipper design or assembly before products reach the consumer.

• Product Development and Specification
  This standard supports product engineers and designers in selecting, specifying, or developing zippers for apparel, luggage, outdoor gear, and industrial textiles. By referencing standard test data, buyers can make informed decisions and ensure products meet desired durability standards.

• Regulatory Compliance
  As an internationally harmonized test standard, ASTM D2061 aligns with the WTO Technical Barriers to Trade (TBT) principles. This facilitates trade and market access by ensuring zipper products meet consistent and recognized performance benchmarks globally.

• Comparative Testing Between Laboratories
  The standard provides guidance for resolving discrepancies in test results, including recommendations for statistical sampling and analysis, thereby supporting reliable third-party testing and certification.

Related Standards

• ASTM D2050 – Terminology Relating to Textile Subassemblies
• ASTM D2051–D2054, D2057–D2059/D2059M, D2060, D2062 – Related to zipper durability, colorfastness, operability, resistance to salt spray, and measuring zipper dimensions
• ASTM D1776/D1776M – Practice for Conditioning and Testing Textiles
• ASTM D123 – General textile terminology

These referenced documents, when used alongside ASTM D2061, provide a comprehensive approach to evaluating not only the strength but also other critical properties (such as durability and colorfastness) essential for zipper performance.

---

Using the ASTM D2061 zipper strength test methods ensures textile products have reliable, durable fastening solutions. Incorporating these standardized tests into manufacturing and supply chain processes helps meet rigorous quality and compliance requirements, contributing to customer satisfaction and regulatory acceptance worldwide.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D2061 − 07 (Reapproved 2021)
Standard Test Methods for
Strength Tests for Zippers
This standard is issued under the fixed designation D2061; 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 D76/D76M Specification for Tensile Testing Machines for
Textiles
1.1 These test methods cover the determination of the
D123 Terminology Relating to Textiles
strengths for zipper and zipper parts. All methods are not
D1776/D1776M Practice for Conditioning and Testing Tex-
suitable for use with all kinds of zipper.The restrictions, if any,
tiles
are indicated in the scope for each individual test method. The
D2050 Terminology Relating to Subassemblies Used in the
test methods appear as follows:
Manufacture of Textiles
Sections
D2051 Test Method for Durability of Finish of Zippers to
Holding Strengths of Separable Units 25–32 Laundering
Holding Strength of Slider Lock 92 – 100
D2052 Test Method for Colorfastness of Zippers to Dry-
Holding Strength of Stops 17–24
cleaning
Resistance to Angular Pull-Off of Slider Pull 82–91
Resistance to Cushioned Compression of Sliders 33–42 D2053 Test Method for Colorfastness of Zippers to Light
Resistance to Pull-Off of Slider Pull 72–81
D2054 Test Method for Colorfastness of Zipper Tapes to
Resistance to Twist of Pull and Slider 52–61
Crocking
Slider Deflection and Recovery 43–51
Strength of Chains and Elements 9–16
D2057 Test Method for Colorfastness of Zippers to Laun-
Torsional Resistance of Slider Pull for Removal of 62–71
dering
Components
D2058 Test Method for Durability of Finish of Zippers to
1.2 The values stated in SI units are to be regarded as
Drycleaning
standard. The values given in parentheses after SI units are
D2059/D2059M Test Method for Resistance of Zippers to
provided for information only and are not considered standard.
Salt Spray (Fog)
1.3 This standard does not purport to address all of the
D2060 Test Methods for Measuring Zipper Dimensions
safety concerns, if any, associated with its use. It is the
D2062 Test Methods for Operability of Zippers
responsibility of the user of this standard to establish appro-
2.2 U. S. Government Standard:
priate safety, health, and environmental practices and deter-
MIL-105D Sampling Procedures and Tables for Inspection
mine the applicability of regulatory limitations prior to use.
by Attributes
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard- 3. Terminology
ization established in the Decision on Principles for the
3.1 Definitions:
Development of International Standards, Guides and Recom-
3.1.1 For definitions of zipper terms used in this standard,
mendations issued by the World Trade Organization Technical
refer to Terminology D2050. For definitions of other textile
Barriers to Trade (TBT) Committee.
terminology used in this standard, refer to Terminology D123.
2. Referenced Documents
4. Significance and Use
2.1 ASTM Standards:
4.1 Theusefulnessofazipperinservicecanbeevaluatedby
thesetests.Noonetestdeterminesthesuitabilityofazipperfor
a specific end use. Since the tests are inter-related more than
These test methods are under the jurisdiction of ASTM Committee D13 on
one may be needed for a complete evaluation.
Textiles are the direct responsibility of Subcommittee D13.54 on Subassemblies and
were developed in cooperation with the American Fastener and Closure Assn. 4.2 These methods are considered satisfactory for accep-
Current edition approved July 1, 2021. Published August 2021. Originally
tance testing of commercial shipments because the methods
approved in 1961. Last previous edition approved in 2013 as D2061 – 07 (2013).
have been used extensively in the trade for this purpose, and
DOI: 10.1520/D2061-07R21.
For referenced ASTM standards, visit the ASTM web site, www.astm.org, or
contact ASTM Customer Service at [e-mail]. ForAnnual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
the ASTM web site. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2061 − 07 (2021)
because estimates of current between-laboratory precision are 6.1.1 Reliable Estimate of v—When there is a reliable
acceptable in most cases. estimate of v based upon extensive past records for similar
4.2.1 If there are differences of practical significance be- materials tested in the users laboratory as directed in the
tween reported test results for two laboratories (or more), method, calculate n using Eq 1.
comparative test should be performed to determine if there is a
2 2 2 2
n 5 t 3v /A 5 0.0270 v (1)
statistical bias between them, using competent statistical assis-
where:
tance. As a minimum, the test samples should be used that are
n = number of specimens (rounded upward to a whole
as homogeneous as possible, that are drawn from the material
from which the disparate test results were obtained, and that number),
v = reliable estimate of the coefficient of variation of
are randomly assigned in equal numbers to each laboratory for
individual observations in the users laboratory
testing. Other materials with established test values may be
under conditions of single-operation precision,
used for this purpose.The test results from the two laboratories
t = 1.645, the value of Student’s t for infinite degrees
should be compared using a statistical test for unpaired data, at
of freedom, two-sided limits and a 90 % probabil-
a probability level chosen prior to the testing series. If a bias is
ity level (t = 2.706),
found, either its cause must be found and corrected, or future
A = 10.0 % of the average, the value of the allowable
test results must be adjusted in consideration of the known
variation, and
bias.
2 2
0.0270 = a value calculated from t /A
4.3 The method(s) in the standard along with those in Test
6.1.2 No Reliable Estimate of v—When there is no reliable
Methods D2051, D2052, D2053, D2054, D2057, D2058,
estimate of v for the users laboratory, Eq 1 should not be used
D2059/D2059M, D2060, and D2062 are a collection of proven
directly. Instead, specify the number of specimens shown in
test methods. They can be used as aids in the evaluation of
Table 1. This number of specimens is calculated using values
zippers without the need for a thorough knowledge of zippers.
of v which are somewhat larger values of v than are usually
The enumerated test methods do not provide for the evaluation
found in practice. When a reliable estimate of v for the users
of all zipper properties. Besides those properties measured by
laboratory becomes available, Eq 1 will usually specify fewer
means of the enumerated test methods there are other proper-
than the number of specimens shown in Table 1.
ties that may be important for the satisfactory performance of
a zipper. Test methods for measuring those properties have not
6.2 Attributes—For methods for which the test result merely
been published either because no practical methods have yet
states whether there is conformance to the criteria for success
been developed or because a valid evaluation of the informa-
specified in the procedure, take the number of specimens
tion resulting from existing unpublished methods requires an
directed in MIL Standard 105D for the level of inspection
intimate and thorough knowledge of zippers.
agreed upon by the purchaser and the seller. The methods to
which these instructions apply are as follows:
5. Sampling
Sections
5.1 LotSample—Asalotsampleforacceptancetesting,take
Resistance to Cushioned Compression of Sliders 30–38
at random the number of individual containers from each
Resistance to Pull-Off of Slider Pull 56–74
shipping carton as directed in an applicable material specifi- Resistance to Angular Pull-Off of Slider Pull 75–83
Holding Strength of Slider Lock 84–91
cation or other agreement between the purchaser and the
supplier. Consider individual containers from each shipping
7. Test Specimen
carton to be the primary sampling units.
7.1 The test specimen may consist of a completely as-
NOTE 1—An adequate specification or other agreement between the
sembledzipper,lengthofchain,oracomponent,asspecifiedin
purchaserandsupplierrequirestakingintoaccountthevariabilitybetween
the individual method. Unless otherwise specified the zipper
shipping cartons and between zippers in a container to provide a sampling
shall not be attached to an application when testing.
plan with a meaningful producer’s risk, consumer’s risk, acceptable
quality level, and limiting quality level.
8. Conditioning
5.2 Laboratory Sample and Test Specimens—As a labora-
tory sample for acceptance testing, take the number of zippers
8.1 Bring the specimens to moisture equilibrium for testing
specified in Section 6 at random from each container in the lot in the standard atmosphere for testing textiles as directed in
sample. Consider the zippers as both the laboratory sample and Practice D1776/D1776M unless otherwise specified (see 38.1,
the test specimens. 48.1, 57.1, and 87.1). Preconditioning is not required for
zippers other than those made of nylon.
6. Number of Specimens
STRENGTHS OF CHAINS AND ELEMENTS
6.1 Variables—Take a number of zippers per individual
container from each shipping carton such that the user may
9. Scope
expect at the 90 % probability level that the test result for an
9.1 These test methods cover the determination of the
individual container is no more than 10 % of the average,
strengths of zipper chains and elements in tensile tests.
above or below the true average for the individual container.
Determine the number of zippers per individual container as 9.2 The element pull-off and element slippage tests apply to
follows: separate element zippers only.
D2061 − 07 (2021)
TABLE 1 Specimens Required Under Conditions of Known and Unknown Variability in User’s Laboratory Units as Indicated
No Reliable Estimate of v
Allowable Variation Equation for n, Using a Reliable
Property
Number of
A
Two-Sided Estimate of v
Basis
Specimens
Strength of chains and elements:
Chain crosswise strength 10.0 n = 0.027 × v 2 v = 8.45
Element pull-off 10.0 n = 0.027 × v 5 v = 12.56
Element slippage, lengthwise 10.0 n = 0.027 × v 7 v = 14.97
Holding strength of stops:
Top stop, holding 10.0 n = 0.027 × v 17 v = 24.77
Bottom stop holding, slider 10.0 n = 0.027 × v 22 v = 28.41
Bottom stop holding, crosswise 10.0 n = 0.027 × v 8 v = 16.16
Bottom stop holding, stringer separation 10.0 n = 0.027 × v 7 v = 15.60
Bridge top stop, stringer separation 10.0 n = 0.027 × v 31 v = 33.75
Holding strength of separable units:
Separable pin 10.0 n = 0.027 × v 7 v = 15.46
Fixed retainer 10.0 n = 0.027 × v 8 v = 16.34
Separating unit—crosswise 10.0 n = 0.027 × v 4 v = 10.70
Slider deflection and recovery:
2 B
mouth 10.0 n = 0.027 × v v = 93.11
2 B
pull 10.0 n = 0.027 × v v = 48.20
2 B
Resistance to twist of pull and slider: 10.0 n = 0.027 × v v = 51.4
A
The values of v in Table 1 are somewhat larger than will be usually found in practice (see 6.1.2).
B
No standard number of specimens is given for these tests since they are quite variable and are not recommended for acceptance testing except where the laboratories
of the purchaser and the seller have established their precision and bias, if any.
10. Summary of Test Method cannot be used interchangeably. In case of controversy, the
CRE method shall prevail.
10.1 Crosswise Strength—The ability of a zipper chain to
withstand lateral stress is measured by loading to destruction a 12.2 Jaws—The back jaws of the clamps on the tensile
25.4 mm (1 in.) section of a specimen in a tensile testing testing machine shall be at least the same width as the front
machine equipped with clamps having special jaws. jaws. The front jaws shall be 25.4 mm (1 in.) wide and have
hardened faces with horizontal grooves 1.6 mm ( ⁄16 in.) apart,
10.2 Element Pull-Off—The gripping strength of a element
0.38mm(0.015in.)deep,andbeofaV-shapewithanincluded
around the bead is determined by pulling a single element from
angle of 90°.
the bead at right angles to the stringer using a tensile testing
machine fitted with a specially designed fixture. 12.3 Element Pull-off Fixture, designed to grasp the head
of the element by two members as shown in Fig. 1. The fixture
10.3 Element Slippage—The ability of a element to resist
must be designed to fit the element under test so as to avoid
longitudinal movement along the bead of the tape is deter-
element distortion.
mined with a tensile testing machine fitted with a specially
designed fixture. 12.4 Element Slippage Fixture, consisting of a flat plate
1 1
approximately 6 mm ( ⁄4 in.) wide and 2 mm ( ⁄16 in.) thick
11. Significance and Use
which is twisted 90° midway of its length and bent at one end
11.1 Crosswise Strength—This test method may be used to through a 90° angle to give the fixture an “L” shape. The short
leg of the “L” shall be slotted so that the two prongs thus
determine crosswise strength which measures the resistance of
a zipper to such failures as tape rupture, unmeshing, or element formed will clear the bead and slip under a element in order to
pull it along the bead as shown in Fig. 2.
separation when the zipper is side stressed during use.
11.2 Element Pull-off—This test method may be used to
13. Test Specimen
determine element strength which measures a element’s ability
13.1 The test specimen shall consist of a completely as-
to resist being fractured or pulled from the bead of the tape
sembled zipper or a piece of chain at least 127 mm (5 in.) long.
when the zipper is side stressed during use.
11.3 Element Slippage—This test method may be used to
14. Procedure
determine element attachment security and measures a el-
14.1 Chain Crosswise Strength—Secure the tapes of the
ement’s ability to remain on the tape bead in proper position to
zipper or chain in the clamps of the tensile testing machine
adjacent elements so that zipper operation can be maintained.
with the edges of the jaws parallel to the chain and approxi-
mately 3 mm ( ⁄8 in.) from the outer edge of the interlockable
12. Apparatus
elements or the outer edge of the beads if the bead extends
12.1 Tensile Testing Machine—ACRE type testing machine
beyondtheelements.Theendsofthefrontjawsshallbeatleast
conforming to Specification D76/D76M with a rate-of-traverse
25mm(1in.)fromtheslider,stopsorendofthemeshedchain.
of 305 mm 6 10 mm (12 in. 6 0.5 in.)/min. If preferred, the
use of a CRT tensile testing machine is permitted. There may
be no overall correlation between the results obtained with the
Drawings of the apparatus used in this test method are available from most
CRE and CRT machines. Consequently, the two machines zipper manufacturers upon request.
D2061 − 07 (2021)
pulled off or other failure occurs. Record the nature of the
failure and the load at failure to the nearest 0.4 N (0.1 lbf).
14.3 Element Slippage, Lengthwise—The test specimen
shall be cut to approximately 127 mm (5 in.) in length.
Separate the chain into stringers and hold a stringer so the
elements are positioned as in Fig. 2. Remove the second
element from the top of the stringer, taking care not to damage
the bead. Cut through the bead and the tape in the width
direction below the first element and above the removed
element. The tape and bead may be cut either partially or
completely across as long as the element to be tested is not
hindered in its movement along the bead. Cut the tape with
sharp scissors, cutters or nippers using single stroke, ignoring
blooming if it occurs. The element to be tested is the one just
below the element that was removed. Secure the element
slippage fixture (Fig. 2) in the top clamp and position the two
prongs at the end of the short leg of the “L” in horizontal
alignment underneath the element. Secure the stringer in the
lower clamp of the testing machine in vertical alignment,
positioning the clamps approximately 76 mm (3 in.) below the
“L” of the fixture in the upper clamp.Apply an increasing load
until the element slips off the end of the cut bead or until other
FIG. 1 Fixture for Element Pull-Off Test
failure occurs. Record the nature of the failure and the load at
failure to the nearest 0.4 N (0.1 lbf).
15. Report
15.1 State that the specimens were tested as directed in
Sections9–16 of Test Methods D2061. Describe the material
or product sampled and the method of sampling used.
15.2 Report the following information:
15.2.1 The specific property (or properties) evaluated,
15.2.2 Number and description of specimens tested, and
15.2.3 The observed values and nature of failures of each
specimen.
16. Precision and Bias
16.1 Interlaboratory Test Data —An interlaboratory test
was runin which four laboratories each tested eight specimens,
per operator, from each of two materials. Each laboratory used
two operators to test each material. All 64 specimens of each
material came from the same sample. The components of
variance expressed as coefficients of variation, calculated as
percentage of the average were:
Single- Within- Between-
Operator Laboratory Laboratory
FIG. 2 Fixture for Element Slippage Test A
Component Component Component
Chain Crosswise Strength 6.04 0 4.82
Element Pull-Off 8.97 5.56 0
Element Slippage, Lengthwise 10.69 0 0
Apply an increasing load until the elements pull off the bead,
until the tape separates, or until failure of some other kind A
All the within laboratory component is attributable to the same operator testing at
occurs. Record the nature of the failure and the breaking load
different times.
to the nearest 2.2 N (0.5 lbf).
16.2 Precision—For the components of variance reported in
14.2 Element Pull-Off—Secure the element pull-off fixture 16.1, two averages of observed values should be considered
(Fig.1)inthetopclampofthetestingmachine.Thenadjustthe
fixture to grasp a single element on a stringer. Secure the
stringer in the bottom clamp of the testing machine as
Supporting data have been filed at ASTM International Headquarters and may
described in 14.1.Apply an increasing load until the element is be obtained by requesting Research Report RR:D13-1018.
D2061 − 07 (2021)
significantly different at the 90 % probability level if the which measures the ability of the bottom stop to hold the two
difference equals or exceeds the critical differences listed in stringers of the chain together when the zipper is side stressed
Table 2. at the bottom stop.
19.4 Bottom Stop Holding, Stringer Separation—This test
NOTE 2—To convert the values in Table 2 to units of measure, multiply
the average of the two specific sets of data being compared by the critical
method may be used to determine bottom stop attachment
difference expressed as a decimal fraction.
strength,whichmeasurestheabilityofthebottomstoptoresist
NOTE 3—The tabulated values of the critical differences should be
failure caused by such things as tape bead rupture, element
considered to be a general statement particularly with respect to between-
separation from bead or bottom stop displacement due to stress
laboratory precision. Before a meaningful statement can be made about
applied through the stringers.
two specific laboratories, the amount of statistical bias, if any, between
themmustbeestablishedwitheachcomparisonbeingbasedonrecentdata
19.5 Bridge Top Stop, Stringer Separation—This test
obtained on randomized specimens from one sample of the material to be
method may be used to determine bridge top stop attachment
tested.
strength, which measures the ability of the bridge top stop to
16.3 Bias—No justifiable statement can be made on the bias
remain in place holding the stringers of a zipper together and
of the procedures in Test Methods D2061 for determining the
limiting slider travel when the stop is stressed through the
strength of zipper chains and elements, since the true value of
stringers.
the properties cannot be established by an accepted referee
method.
20. Apparatus
HOLDING STRENGTHS OF STOPS
20.1 Testing Machine, as specified in 12.1.
20.2 Fixture, with a curved end as shown in Fig. 3 to hook
17. Scope
the pull of the slider.
17.1 These test procedures are used to determine the hold-
ing strengths of various types of zipper stops.
21. Test Specimen
21.1 The test specimen shall consist of a completely as-
18. Summary of Test Method
sembled zipper.
18.1 The ability of stops to perform their intended purpose
is determined through the use of five different methods which
22. Procedure
simulate the important stresses encountered in the end use of
22.1 In all tests, take care to prevent interference by any
zippers.
locking devices on the slider.
19. Significance and Use
22.2 Top Stop Holding—Secure the fixture in the upper
clamp of the testing machine and hook the pull of the slider on
19.1 Top Stop Holding—This test method may be used to
the fixture (Fig. 3). Position the slider body at the point where
determine top stop attachment strength which measures the
normally checked in its free movement by the stop or stops to
ability of the top stop to prevent travel of the slider beyond the
be tested. Secure the zipper in the lower clamp of the testing
end of the chain.
machine as illustrated in Fig. 4. The distance between the top
19.2 Bottom Stop Holding, Slider—This test method may be
edge of the lower clamp and mouth of the slider shall be
used to determine bottom stop attachment strength, which
approximately 76 mm (3 in.). Apply an increasing load until
measures the ability of the bottom stop to resist failure caused
the stop or stops pull off, until the tape breaks, or until failure
by stress applied longitudinally to the bottom stop through the
of some other kind occurs. Record the nature of the failure and
slider.
the load at failure to the nearest 2.2 N (0.5 lbf) for values under
19.3 Bottom Stop Holding, Crosswise—This test method 222 N (50 lbf) and to the nearest 4.4 N (1 lbf) for values 222 N
may be used to determine bottom stop attachment strength, and over.
TABLE 2 Critical Differences for the Properties Listed
Critical Differences, Percent of Grand Average for the Conditions Noted
Number of Observations in
Single-Operator Within-Laboratory Between-Laboratory
Each Average
Precision Precision Precision
Chain Crosswise Strength 1 14.1 14.1 18.0
3 8.1 8.1 13.8
5 6.3 6.3 12.9
10 4.4 4.4 12.1
Element Pull-off 1 20.9 24.5 24.5
3 12.1 17.7 17.7
5 9.3 15.9 15.9
10 6.6 14.5 14.5
Element Slippage, Lengthwise 1 24.9 24.9 24.9
3 14.4 14.4 14.4
5 11.1 11.1 11.1
10 7.9 7.9 7.9
D2061 − 07 (2021)
FIG. 3 Fixture for Test for Holding Strength of Top Stop
FIG. 5 Bottom Stop Holding Strength Test
FIG. 6 Bottom Stop Holding, Crosswise Test
elements adjacent to but not under the bottom stop for a
distance of approximately 13 mm ( ⁄2 in.). Secure the tapes of
the zipper in the clamps of the testing machine with the edges
of the jaws parallel to and approximately 3 mm ( ⁄8 in.) from
FIG. 4 Top Stop Holding Strength Test the sides of the bottom stop, which shall be centrally located in
the clamps as shown in Fig. 6. Apply the load until the stop
pulls apart, until the tape breaks, or until failure of some other
22.3 Bottom Stop Holding, Slider—Secure the fixture in the kind occurs. Record the nature of the failure and the load at
upper clamp of the testing machine and hook the pull of the failure to the nearest 2.2 N (0.5 lbf) for values under 222 N
slider on the fixture (Fig. 3). Position the slider at the point (50 lbf) and to the nearest 4.4 N (1 lbf) for values of 222 N and
where normally checked in its free movement by the bottom
over.
stop to be tested. Secure the two stringers in the lower clamp
22.5 Bottom Stop Holding, Stringer Separation—Position
of the testing machine as illustrated in Fig. 5, taking care to
the slider body so that its mouth is against the bottom of the
equalize the lengths of the two stringers between the clamps.
stop to be tested. In the case of the entering type bottom stop,
The angle included between the stringers shall be such as to
position the slider at the point where normally checked in its
prevent the catching of elements on the flanges or on the
freemovement.Settheopposingclampsofthetestingmachine
diamond. The distance between the top edge of the lower
approximately 76 mm (3 in.) apart and secure one of the
clamp and the nearest surface of the slider body shall be
stringers in the upper clamp and the other in the lower clamp
approximately 76 mm (3 in.). Apply an increasing load until
of the tensile testing machine approximately 76 mm apart.
the stop pulls off, until the tape breaks, or until failure of some
Secure the stringers in the upper and lower clamps of the
other kind occurs. Record the nature of the failure and the load
testing machine with the slider body positioned along the axis
at failure to the nearest 2.2 N (0.5 lbf) for values under 222 N
of the clamps and midway between them as shown in Fig. 7.
(50 lbf) and to the nearest 4.4 N (1 lbf) for values 222 N and
Apply an increasing load until the stop pulls off, until the tape
over.
breaks, or until failure of some other kind occurs. Record the
22.4 Bottom Stop Holding, Crosswise—Remove the slider nature of the failure and load at failure to the nearest 2.2 N
from the zipper. Open the chain by pulling the stringer apart all (0.5 lbf) for values under 222 N (50 lbf) and to the nearest
the way to the bottom stop. From both stringers remove the 4.4 N (1 lbf) for values 222 N and over.
D2061 − 07 (2021)
23. Report
23.1 State that the specimens were tested as directed in
Sections17–24ofTestMethodsD2061.Describethematerial
or product sampled and the method of sampling used.
23.2 Report the following information:
23.2.1 The specific property (or properties) evaluated,
23.2.2 Number and description of specimens tested, and
23.2.3 The observed values and nature of failures of each
specimen.
24. Precision and Bias
24.1 Interlaboratory Test Data —An interlaboratory test
was conducted as described in 16.1. The components of
variance expressed as coefficients of variation, percent relative,
were calculated to be:
Single- Within- Between-
Operator Laboratory Laboratory
A
Component Component Component
Top Stop Holding 17.35 0 0
Bottom Stop Holding, Slider 20.29 0 12.22
FIG. 7 Bottom Stop Holding, Stringer Separation Test
Bottom Stop Holding, Crosswise 11.54 6.09 0
Bottom Stop Holding, Stringer 11.14 0 3.97
Separation
Bridge Top Stop, Stringer 24.11 0 0
Separation
A
All the within laboratory component is attributable to the same operator testing at
different times.
24.2 Precision—For the components of variance reported in
24.1, two averages of observed values should be considered
significantly different at the 90 % probability level if the
difference equals or exceeds the critical differences listed in
Table 3 (Note 2 and Note 3).
24.3 Bias—No justifiable statement can be made on the bias
of the procedures in Test Methods D2061 for determining the
holdingstrengthsofstops,sincethetruevalueoftheproperties
cannot be established by an accepted referee method.
HOLDING STRENGTHS OF SEPARABLE UNITS
25. Scope
25.1 These test methods cover the determination of the
holding strengths of separable units of zipper and parts thereof.
26. Summary of Test Methods
26.1 The strength of attachment of the separable unit
FIG. 8 Bridge Top Stop, Stringer Separation Test
components is determined by three test methods that simulate
important stresses encountered in end use of zippers.
22.6 BridgeTopStop,StringerSeparation—Withtheoppos-
27. Significance and Use
ing clamps of the tensile testing machine set approximately 76
27.1 Separable Pin, Pull-off—This test method may be used
mm (3 in.) apart, separate the two stringers and secure them in
todetermineseparablepinattachmentstrengthwhichmeasures
the opposing clamps of the testing machine. Position the stop
the ability of the separable pin to resist displacement on the
along the axis of the clamps and midway between them as
tape bead when a longitudinal force is applied.
shown in Fig. 8. Apply an increasing load until the stop pulls
off, until the tape breaks, or until failure of some other kind 27.2 Fixed Retainer, Pull-off—Thistestmethodmaybeused
occurs. Record the nature of the failure and the load at failure todeterminefixedretainerattachmentstrengthwhichmeasures
to the nearest 2.2 N (0.5 lbf) for values under 222 N (50 lbf) the ability of the fixed retainer to resist displacement on the
and to the nearest 4.4 N (1 lbf) for values 222 N and over. tape bead when a longitudinal force is applied.
D2061 − 07 (2021)
TABLE 3 Critical Differences for the Properties Listed
Critical Differences, Percent of Grand Average for the Conditions Noted
Number of
Observations in Each
Single-Operator Within-Laboratory Between-Laboratory
Average
Precision Precision Precision
Top Stop Holding 1 40.4 40.4 40.4
3 23.3 23.3 23.3
5 17.9 17.9 17.9
10 12.6 12.6 12.6
Bottom Stop Holding, Slider 1 47.2 47.2 55.1
3 27.2 27.2 39.4
5 21.0 21.0 35.4
10 14.8 14.8 32.1
Bottom Stop Holding, Crosswise 1 26.8 30.3 30.3
3 15.5 21.0 21.0
5 12.0 18.6 18.6
10 8.5 16.5 16.5
Bottom Stop Holding, Stringer Separation 1 25.9 25.9 27.5
3 15.0 15.0 17.6
5 11.6 11.6 14.8
10 8.2 8.2 12.4
Bridge Top Stop, Stringer Separation 1 56.1 56.1 56.1
3 32.3 32.3 32.3
5 25.1 25.1 25.1
10 17.1 17.1 17.1
27.3 Separating Unit, Crosswise—This test method may be 28.2 Separable Pin Fixture, as shown in Fig. 9 for holding
used to determine meshed separating unit attachment strength the separable pin in the pull-off test.
which measures the ability of the separating unit to resist 4
28.3 Fixed Retainer Fixture, as shown in Fig. 10 for
failure due to separation from the tape bead, tape fracture or
holding the fixed retainer in the pull-off test.
separation of the unit caused by lateral stressing of the zipper
at the separating unit.
29. Test Specimen
29.1 The test specimen shall consist of a completely as-
28. Apparatus
sembled zipper.
28.1 Testing Machine, as specified in 12.1.
30. Procedure
30.1 Separable Pin, Pull-Off—Separate the two stringers
and, adjacent to the separable pin, remove one or more
elements from the stringer. Secure the separable pin fixture
FIG. 9 Fixture for Separable Pin Pull-Off Test FIG. 10 Fixture for Retainer Pull-Off Test
D2061 − 07 (2021)
(Fig. 9) in the upper clamp of the testing machine. Then seat
the separable pin on the fixture notch as shown in Fig. 9. With
a distance of approximately 76 mm (3 in.) between the seated
end of the pin and the top of the lower clamp, secure the
stringer in the lower clamp.Apply an increasing load until the
separable pin pulls off, until the tape breaks, or until failure of
someotherkindoccurs.Recordthenatureofthefailureandthe
load at failure to the nearest 2.2 N (0.5 lbf) for values under
222 N (50 lbf) and to the nearest 4.4 N (1 lbf) for values 222 N
FIG. 12 Separating Unit, Crosswise Test
and over.
30.2 Fixed Retainer, Pull-Off—Secure the fixture (Fig. 10)
in the upper clamp of the testing machine. Separate the two
stringers and position the fixed retainer on the upper edges of
32. Precision and Bias
the slot of the fixture and, with an approximate 76 mm (3 in.)
32.1 Interlaboratory Test Data —An interlaboratory test
distance between the lower edge of the fixed retainer and the
was conducted as described in 16.1. The components of
upper edge of the lower clamp, secure the stringer in the lower
variance expressed as coefficients of variation, percent relative,
clamp as shown in Fig. 11. Apply an increasing load until the
were calculated to be:
retainer pulls off, until the tape breaks, or until failure of some
other kind occurs. Record the nature of the failure and load at
Single- Within- Between-
Operator Laboratory Laboratory
failure to the nearest 2.2 N (0.5 lbf) for values under 222 N
Component Component Component
(50 lbf) and to the nearest 4.4 N (1 lbf) for values 222 N and
over.
Separable Pin, Pull-Off 11.04 0 0
Fixed Retainer, Pull-Off 11.67 7.57 0
30.3 Separating Unit, Crosswise—Secure the tapes of the
Separating Unit, Crosswise 7.64 0 2.87
zipperintheclampsofthetestingmachineasshowninFig.12,
32.2 Precision—For the components of variance reported in
with the edges of the jaws parallel to, and approximately 3 mm
32.1, two averages of observed values should be considered
( ⁄8 in.) from the sides of the separating unit, whether the latter
significantly different at the 90 % probability level if the
is of a fixed or movable type. Position the separating unit so
following difference equals or exceeds the differences listed in
that the exposed end of the separable pin is aligned with the
Table 4 (Notes 2 and 3).
sides of the front jaws as shown in Fig. 12.Apply the load until
32.3 Bias—No justifiable statement can be made on the bias
the separating unit comes apart, until the tape breaks or until
of the procedures in Test Methods D2061 for determining the
failure of some other kind occurs. Record the nature of the
holding strengths of separable units, since the true value of the
failure and the load at failure to the nearest 2.2 N (0.5 lbf) for
properties cannot be established by an accepted referee
values under 222 N (50 lbf) and to the nearest 4.4 N (1 lbf) for
method.
values 222 N and over.
RESISTANCE TO CUSHIONED
31. Report
COMPRESSION OF SLIDERS
31.1 State that the specimens were tested as directed in
Sections25–32 of Test Methods D2061.
33. Scope
31.2 Report the following information:
33.1 This test method covers the determination of the
31.2.1 The specific property (or properties) evaluated,
compression resistance of a slider assembled on a zipper chain,
31.2.2 Number and description of specimens tested, and
with the pull in either the normal flat position or the 180°
31.2.3 The observed values and nature of failures of each
reverseposition,whencushionedloadsareappliedperpendicu-
specimen.
larly to top and bottom slider planes.
34. Summary of Test Method
34.1 The lower platen of a compression tester is cushioned
withaneoprenepad.Thespecimenislaidonthepadandaload
applied. The effects of operability of the zipper is then
determined.
35. Significance and Use
35.1 Resistance to Cushioned Compression of Sliders—This
test method may be used to determine the crushing resistance
of a slider which measures the ability of a slider to resist
crushing, for example in pressing the end item, which could
FIG. 11 Fixed Retainer Pull-Off Test cause the slider to malfunction or become inoperative.
D2061 − 07 (2021)
TABLE 4 Critical Differences for the Properties Listed
Critical Differences, Percent of Grand Average for the Conditions Noted
Number of
Observations in Each
Single-Operator Within-Laboratory Between-Laboratory
Average
Precision Precision Precision
Separable Pin, Pull-Off 1 25.7 25.7 25.7
3 14.8 14.8 14.8
5 11.5 11.5 11.5
10 8.1 8.1 8.1
Fixed Retainer, Pull-Off 1 27.2 32.4 32.4
3 15.7 23.6 23.6
5 12.2 21.4 21.4
10 8.6 19.6 19.6
Separating Unit, Crosswise 1 17.8 17.8 19.0
3 10.2 10.2 12.2
5 7.9 7.9 10.4
10 5.5 5.5 8.7
FIG. 13 Test for Slider Resistance to Cushioned Compression
36. Apparatus 38. Conditioning
36.1 Compression Testing Machine —A testing machine
38.1 No conditioning is required.
with upper and lower platens, one of which may be fixed and
the other movable. The platens shall be hardened steel, 51 mm
39. Procedure
by 51 mm by 25 mm (2 in. by 2 in. by 1 in.) and their opposite
39.1 Test the zipper for operability as directed in Opening
faces shall be smooth and parallel to each other as shown in
and Closing in Test Methods D2062.
Fig. 13. The lower platen shall have attached to its entire
1 39.2 Position the specimen centrally on the lower platen.
surface a piece of neoprene rubber 6 mm ( ⁄4 in.) in thickness
Placethepullinthenormalflatposition,lyingonthetopofthe
and of 65 Durometer hardness. The compression testing
slider as shown in Fig. 13. Apply a compression force at a
machineshallbedesignedtopermittheapplicationofaloadto
rate-of-traverse of approximately 13 mm ( ⁄2 in.)/min until it
the platens at a rate-of-traverse of approximately 13 mm
reaches the load required by the applicable specification.
( ⁄2 in.)⁄min. The load shall be measurable in increments of 44
Release the compression force, remove the specimen from the
N (10 lbf).
apparatus and test it for operability as directed in 39.1.
37. Test Specimen
39.3 On the second specimen, proceed as directed in 39.2
37.1 The test specimen shall consist of a slider assembled
but with the pull of the slider 180° in the reverse position.
on the zipper chain with which it is to be used. Two specimens
39.4 Test locking-type sliders that satisfactorily pass the
are required.
requirements of 39.2 further as directed in Sections 92 – 100.
Thesolesourceofsupplyofasuitablelaboratorypressknowntothecommittee
atthistimeisFredS.Carver,Inc.,Summit,NJ07901.Ifyouareawareofalternative 40. Evaluation
suppliers, please provide this information to ASTM International Headquarters.
40.1 Consider breakage or deformation beyond that permit-
Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. ted by the applicable specification a failure. Examine each
D2061 − 07 (2021)
specimen to determine whether or not there remains the usual
ease of manual movement of the pull.
41. Report
41.1 State that the specimens were tested as directed in
Sections33–42ofTestMethodsD2061.Describethematerial
or product sampled and the method of sampling used.
41.2 Report the following information:
41.2.1 Specific property (or properties) evaluated,
41.2.2 Number and description of specimens tested, and
41.2.3 The observed values and nature of failures of each
specimen.
42. Precision and Bias
42.1 No justifiable statement can be made either on the
precision or on the bias of the procedures in Test Methods
D2061 for testing the resistance to cushioned compression of
zipper sliders since the test result merely states whether there
is conformance to the criteria for success expressed in the
procedure. The precision and bias of Test Methods D2061 for
testing zipper operability are as specified in Test Methods
D2062.
FIG. 14 Fixture for Slider Deflections Test (Mouth)
SLIDER DEFLECTION AND RECOVERY
43. Scope
43.1 These test methods cover two procedures for determin-
ing the resistance of slider planes of zippers to an opening or
spreading force. In one procedure the force is applied to the
mouth of the slider. In the other, which is an alternative
method, the force is applied through the slider pull and back
plane of the slider.
44. Summary of Test Methods
44.1 Fixtures as shown in Figs. 14 and 15 are used with a
tensile testing machine to apply a spreading force on the slider
planes.
45. Significance and Use
45.1 Slider Deflection and Recovery, Mouth—This test
FIG. 15 Fixture for Slider Deflection Test (Pull)
method may be used to determine spreading resistance of a
slider which measures the ability of a slider to retain control of
the chain by resisting the spreading apart of its two halves
whentheslidermouthisstressedduringoperationofthezipper
in the end-product. 46.3 Diamond Spacer, conforming to the requirements
shown in Fig. 16 and used in conjunction with the slider
45.2 Slider Deflection and Recovery, Pull—Thistestmethod
deflection mouth fixture.
may be used to determine spreading resistance of a slider
which measures the ability of a slider to retain control of the 46.4 Nibs, conforming to the requirements shown in Fig. 16
and used in conjunction with the slider deflection mouth
chain by its resistance to the spreading apart of its two halves
when the slider is stressed by a force on the slider pull during fixture.
operation of the zipper in the end-product.
46.5 Slider Deflection Pull Fixture and Dial Gage, as
shown in Fig. 15. The top plate of the fixture shall be changed
46. Apparatus
to suit the size of the slider as shown in Fig. 17.
46.1 Testing Machine, as specified in 12.1.
47. Test Specimen
46.2 Slider Deflection Mouth Fixture —A fixture and dial
gage as shown in Fig. 14. 47.1 The test specimen shall consist of a complete slider.
D2061 − 07 (2021)
Nib Dimensions, in. (mm) Spacer Dimensions, in. (mm)
Zipper Size
AB C D E F G
1 and 2 1.168 2.921 3.125 1.168 2.352 2.921 0.406
(2.540 to 3.556) (0.046) (0.115) (0.125) (0.046) (0.093) (0.115) (0.016)
3 and 4 1.702 3.937 4.750 1.829 3.125 3.937 0.508
(3.581 to 5.080) (0.067) (0.155) (0.187) (0.072) (0.125) (0.155) (0.020)
5 and 6 2.286 5.588 5.537 2.413 4.750 5.588 0.762
(5.105 to 7.620) (0.090) (0.220) (0.218) (0.095) (0.187) (0.220) (0.030)
7, 8 and 9 3.302 8.255 8.712 3.429 7.137 8.255 1.016
(7.645 to 10.160) (0.130) (0.325) (0.343) (0.135) (0.281) (0.325) (0.040)
10 4.699 11.430 9.525 4.826 8.712 11.430 1.524
(10.185 to 12.700) (0.185) (0.450) (0.375) (0.190) (0.343) (0.450) (0.060)
FIG. 16 Dimensions of Nib and Spacer
Plate Dimensions, mm (in.)
Dimension Zipper Sizes
1 and 2 3 and 4 5 and 6 7, 8, and 9 10
A 2.540 3.556 4.953 7.620 10.160
(0.100) (0.140) (0.195) (0.300) (0.400)
B 1.168 1.702 2.286 3.302 4.699
(0.046) (0.067) (0.090) (0.130) (0.185)
C 7.620 10.160 12.700 18.415 25.400
(0.300) (0.400) (0.500) (0.725) (1.000)
D 2.159 3.048 4.318 6.350 8.890
(0.085) (0.120) (0.170) (0.250) (0.350)
E 0.525 12.065 13.970 19.685 22.860
(0.375) (0.475) (0.550) (0.775) (0.900)
F 1.575 2.362 3.175 3.175 3.962
(0.062) (0.093) (0.125) (0.125) (0.156)
FIG. 17 Dimensions of Top Plate
D2061 − 07 (2021)
TABLE 6 Testing Loads for Slider Deflection Tests—Pull Tests
48. Conditioning
Zipper Size Load
48.1 No conditioning is required.
Nlbf
1, 2, 3, 4 89 20
49. Procedure
5, 6 133 30
7, 8, 9, 10 222 50
49.1 Slider Deflection and Recovery, Mouth—See Fig. 16
and, in accordance with the slider size, select the appropriate
diamond spacer and nibs to be used. Insert the selected
samples, except when the bias, if any, of the laboratories of
diamond spacer transversely through the slider as shown in
purchaser and seller has been established.
Fig. 14. Leave the diamond spacer in place throughout the test.
Place the slider mouth over the selected nibs on the slider
51.2 Interlaboratory Test Data —An interlaboratory test
deflection mouth fixture, making certain that the nibs abut the
was conducted as described in 16.1. The components of
diamond spacer.Apply an initial load of 4.4 N (1 lbf) and then
variance expressed as coefficients of variation, percent relative,
set the deflection indicator dial to zero. Apply the load
were calculated to be:
specified for the size of the zipper being tested as shown in
Single- Within- Between-
Table 5 at a constant rate-of-traverse of approximately 13 mm
Operator Laboratory Laboratory
1 Component Component Component
( ⁄2 in.)/min. Read and record the measurement of the deflec-
tion on the dial indicator. Reduce the load to 4.4 N (1 lbf).
Slider Deflection and Recovery, 66.51 25.21 179.85
Again read the measurement on the dial indicator. Record any Mouth
Slider Deflection and Recovery, pull 34.43 0 70.27
reading above zero as the amount of permanent set.
51.3 Precision—For the components of variance reported in
49.2 Slider Deflection and Recovery, Pull—Fasten the slider
51.2, two averages of observed values should be considered
deflection pull fixture in the lower clamp of the tensile testing
significantly different at the 90 % probability level if the
machine. Place the slider to be tested on the fixture so that the
difference equals or exceeds the critical differences listed in
fixture enters the mouth first and the diamond enters the notch
Table 6 (Notes 2 and 3).
of the top plate as shown in Fig. 16. Connect the pull to the top
51.4
...