1、Designation: D4705 12D4705 13Standard 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.
2、 A number 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 Department of Defense.1. Scope1.1 This test method is intended for use in determining
3、 the stitch tearing resistance of leather using a double hole tear. It isparticularly applicable to lightweight leathers. This test method does not apply to wet blue.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions
4、to SI units that 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 responsibilityof the user of this standard to establish appropriate safety and health practices and
5、determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1610 Practice for Conditioning Leather and Leather Products for TestingD1813 Test Method for Measuring Thickness of Leather Test SpecimensD2209 Test Method for Tensile Strength of LeatherD28
6、13 Practice for Sampling Leather for Physical and Chemical Tests3. Significance and Use3.1 This test method is designed to measure the load required to tear leather through two holes in the test specimen. Tannersand leather buyers have found that this test gives an indication of the resistance of le
7、ather to tearing. It is of particular value inestimating the durability of leather to withstand tearing stresses encountered in the manufacture of shoes, garments, andupholstered products. The thickness of the specimen and direction of tear relative to the backbone will affect the uniformity of thet
8、est results. This test method may not apply when the conditions of the test employed differ widely from those specified in the testmethod.4. Apparatus4.1 Testing Machine, as described in Test Method D2209.4.2 Thickness Gage, a dead weight type of thickness gage as described in Method D1813.4.3 Steel
9、 Die, to cut test specimens (as described in 5.1).4.4 Paper Clip, #1/Premium, with wire diameter 0.041 6 0.001 in. (1.04 6 0.0254 mm).5. Sampling Test Specimen5.1 Unless otherwise specified, sample the leather according to Practice D2813.5.2 The specimen shall be a rectangle of leather 2 in. (50.8 m
10、m) 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. The centers of the holes shall be 14 in. (6.35 mm) from the end, 14 in.(6.35 mm) apart, and located equidistant from the center line (length wise) of the specimen. See Fig. 1.1 This tes
11、t method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.07 on Physical Properties.Current edition approved Sept. 1, 2012May 1, 2013. Published October 2012May 2013. Originally approved in 1987. Last previous edition approved in 2005201
12、2 as D4705- 00 (2010). 12. DOI: 10.1520/D4705-12.10.1520/D4705-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM web
13、site.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prio
14、r editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3 The specimen shall be cut with the long
15、 dimension perpendicular to the backbone.6. Conditioning6.1 All specimen shall be conditioned for 48 h and tested in an atmosphere maintained at 73.4 6 3.6F (23 6 2C) and 50 64 % relative humidity and tested under the conditions as described in Practice D1610.7. Procedure7.1 Determine the thickness
16、of the specimen to the nearest 0.001 in. (0.01 mm) on the long axis near one end.7.2 Bend the wire into a “U” shape, preferably by bending over a 14 in. (6.35 mm) rod, and pass the ends through the holesin the specimen so that both ends project from the flesh side of the specimen. Clamp both ends of
17、 the wire in the testing machinegrip, the jaws of which have been covered. Clamp the free end of the specimen in the other grip of the testing machine.7.3 Operate the machine at 10 6 2 in. (254 6 50.8 mm) per minute until the specimen tears. At the instant that the specimenbegins to tear, note and r
18、ecord the load registered by the machine.8. Report8.1 Report the following:8.1.1 Thickness to the nearest 0.001 in. (0.01 mm) reported for each specimen or averaged and reported as the thickness of thesample.8.1.2 The tearing strength of the specimen shall be reported to the nearest 1 lb (0.45 kg).9
19、. Precision and Bias (or Reproducibility)9.1 This test method is adopted from the procedure of the American Leather Chemists Association where it has long been inuse and where it was approved for publication before the inclusion of precision and bias statements was mandated. The originalinterlaborat
20、ory test data is no longer available. The user is cautioned to verify by the use of reference materials, if available, thatthe precision and bias (or reproducibility) of this test method is adequate for the contemplated use.FIG. 1 Test SpecimenD4705 13210. Keywords10.1 leather; stitch tear; stitch t
21、ear strength; strength; tear strengthstrength; 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
22、 patent rights, and the riskof infringement of such rights, are entirely 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
23、either for revision of this standard or for additional standardsand 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 fa
24、ir hearing you shouldmake 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 st
25、andard 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D4705 133
