1、Designation: D 4705 00 (Reapproved 2005)Standard Test Method forStitch Tear Strength of Leather, Double Hole1This standard is issued under the fixed designation D 4705; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method is intended for use i
3、n determining thestitch 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 the standard. The values given in parentheses are providedfo
4、r information only.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 and health practices and determine the applica-bility of regulatory limitations prior to
5、use.2. Referenced Documents2.1 ASTM Standards:2D 1610 Practice for Conditioning Leather and LeatherProducts for TestingD 1813 Test Method for Measuring Thickness of LeatherTest SpecimensD 2209 Test Method for Tensile Strength of LeatherD 2813 Practice for Sampling Leather for Physical andChemical Te
6、sts3. 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 anindication of the resistance of leather to tearing. It is ofparticular value in estimating the du
7、rability 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 willaffect the uniformity of the test results. This test method maynot apply when the conditions of
8、 the test employed differwidely from those specified in the test method.4. Apparatus4.1 Testing Machine, as described in Test Method D 2209.4.2 Thickness Gage, a dead weight type of thickness gage asdescribed in Method D 1813.4.3 Steel Die, to cut test specimens (as described in 5.1).4.4 Paper Clip,
9、 #1/Premium, with wire diameter 0.041 60.001 in. (1.04 6 0.0254 mm).5. Sampling Test Specimen5.1 Unless otherwise specified, sample the leather accordingto Practice D 2813.5.2 The specimen shall be a rectangle of leather 2 in. (50.8mm) in length and 1 in. (25.4 mm) in width with two holes (564in. (1
10、.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. 1.5.3 The specimen shall be cut with the long dimensionperpendicular to the backbon
11、e.6. Conditioning6.1 All specimen shall be conditioned for 48 h in anatmosphere maintained at 73.4 6 3.6F (23 6 2C) and 50 64 % relative humidity and tested under the conditions asdescribed in Practice D 1610.7. Procedure7.1 Determine the thickness of the specimen to the nearest0.5 oz (0.2 mm) on th
12、e long 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 ofthe specimen. Clamp both ends of the wire in the testingmachine grip, the jaws of which hav
13、e been covered. Clamp thefree end of the specimen in the other grip of the testingmachine.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.07 on Physical Properties.Current edition approved April 1, 2005. Published May 2
14、005. Originallyapproved in 1987. Last previous edition approved in 2000 as D 470500.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary p
15、age onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.3 Operate the machine at 10 6 2 in. (254 6 50.8 mm) permin until the specimen tears. At the instant that the specimenbegins to tear, note and record the load re
16、gistered by themachine.8. Report8.1 Report the following:8.1.1 Thickness to the nearest 0.5 oz (0.2 mm) reported foreach specimen or averaged and reported as the thickness of thesample.8.1.2 The tearing strength of the specimen shall be reportedto the nearest 1 lb (0.45 kg).9. Precision and Bias (or
17、 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. Theoriginal interlaboratory test data is no longer
18、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; strength; tearstrength; tearing strengthASTM
19、 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 riskof infringement of such rights, are ent
20、irely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsan
21、d should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee o
22、n 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 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).FIG. 1 Test SpecimenD 4705 00 (2005)2
