1、Designation: D4705 18Standard Test Method forStitch Tear Strength of Leather, Double Hole1This standard is issued under the fixed designation D4705; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method is intended for use in determining th
3、estitch tearing resistance of leather using a double hole tear. It isparticularly applicable to lightweight leathers. This test methoddoes not apply to wet blue.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI
4、units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental pract
5、ices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and
6、 Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1610 Practice for Conditioning Leather and Leather Prod-ucts for TestingD1813 Test Method for Measuring Thickness of LeatherTest SpecimensD2209 Test Method
7、for Tensile Strength of LeatherD2813 Practice for Sampling Leather for Physical andChemical Tests3. Significance and Use3.1 This test method is designed to measure the loadrequired to tear leather through two holes in the test specimen.Tanners and leather buyers have found that this test gives anind
8、ication of the resistance of leather to tearing. It is ofparticular value in estimating the durability of leather towithstand tearing stresses encountered in the manufacture ofshoes, garments, and upholstered products. The thickness ofthe specimen and direction of tear relative to the backbone willa
9、ffect the uniformity of the test results. This test method maynot apply when the conditions of the test employed differwidely from those specified in the test method.4. Apparatus4.1 Testing Machine, as described in Test Method D2209.4.2 Thickness Gage, a dead weight type of thickness gage asdescribe
10、d in Method D1813.4.3 Steel Die, to cut test specimens (as described in 5.1).4.4 Paper Clip, Smooth, with wire diameter 0.041 6 0.002in. (1.04 6 0.05 mm).5. Sampling Test Specimen5.1 Unless otherwise specified, sample the leather accordingto Practice D2813.5.2 The specimen shall be a rectangle of le
11、ather 2 in. (50.8mm) in length and 1 in. (25.4 mm) in width with two holes (564in. (1.98 mm) in diameter on one end of the specimen. Thecenters of the holes shall be14 in. (6.35 mm) from the end,14in. (6.35 mm) apart, and located equidistant from the centerline (length wise) of the specimen. See Fig
12、. 1.5.3 The specimen shall be cut with the long dimensionperpendicular to the backbone.6. Conditioning6.1 All specimen shall be conditioned and tested in anatmosphere as described in Practice D1610.7. Procedure7.1 Determine the thickness of the specimen to the nearest0.001 in. (0.01 mm) on the long
13、axis near one end.7.2 Bend the wire into a “U” shape, preferably by bendingover a14 in. (6.35 mm) rod, and pass the ends through the holesin the specimen so that both ends project from the flesh side of1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct resp
14、onsibility of Subcommittee D31.07 on Physical Properties.Current edition approved Oct. 1, 2018. Published October 2018. Originallyapproved in 1987. Last previous edition approved in 2013 as D4705 - 13. DOI:10.1520/D4705-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orconta
15、ct ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standa
16、rd was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1the spe
17、cimen. Clamp both ends of the wire in the testingmachine grip, the jaws of which have been covered. Clamp thefree end of the specimen in the other grip of the testingmachine.7.3 Operate the machine at 10 6 2 in. (254 6 50.8 mm) perminute until the specimen tears. At the instant that thespecimen begi
18、ns to tear, note and record the load registered bythe machine.8. Report8.1 Report the following:8.1.1 Thickness to the nearest 0.001 in. (0.01 mm) reportedfor each specimen or averaged and reported as the thickness ofthe sample.8.1.2 The tearing strength of the specimen shall be reportedto the neare
19、st 1 lb (0.45 kg).9. Precision and Bias (or Reproducibility)9.1 This test method is adopted from the procedure of theAmerican Leather ChemistsAssociation where it has long beenin use and where it was approved for publication before theinclusion of precision and bias statements was mandated. Theorigi
20、nal interlaboratory test data is no longer available. Theuser is cautioned to verify by the use of reference materials, ifavailable, that the precision and bias (or reproducibility) of thistest method is adequate for the contemplated use.10. Keywords10.1 leather; stitch tear; stitch tear strength; s
21、trength; tearstrength; tearing strengthASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the
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24、ke your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained
25、by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Test SpecimenD4705 182
