1、Designation: D 4704 00 (Reapproved 2005)Standard Test Method forTearing Strength, Tongue Tear of Leather1This standard is issued under the fixed designation D 4704; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. 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 determini
3、ng the tearingstrength of leather by measuring the force required to tear aspecimen cut perpendicular to the surface. 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 providedfor information on
4、ly.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 use.2. Reference
5、d 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 Tests3. Terminolog
6、y3.1 Definitions of Terms Specific to This Standard:3.1.1 tongue tear strengththe load required to tear theleather between two tongues formed by splitting the leatherperpendicular to its surface.4. Significance and Use4.1 Knowledge of the strength of the sample can be adetermining factor for the end
7、 use of the product.5. Apparatus5.1 Testing Machine, as described in Test Method D 2209.5.2 Thickness Gage, a dead weight type of thickness gage asdescribed in Test Method D 1813.5.3 Steel Die, to cut test specimens.6. Sampling and Test Specimens6.1 Unless otherwise specified, sample the leather acc
8、ordingto Practice D 2813.6.2 The specimen shall be a rectangular piece of leather,1 3 4 in. (25.4 3 101.6 mm) by the full thickness of the unit.It shall have a316 in. (4.76 mm) hole located on the long axis1 in. (25.4 mm) from one end and shall be split along its axisfrom the hole to the other end t
9、o form two tongues. Thedirection of the long axis of the specimen relative to thebackbone shall be noted. See Fig. 1.7. Conditioning7.1 All specimens 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 asdesc
10、ribed in Practice D 1610.8. Procedure8.1 Determine the thickness of the specimen to the nearest0.5 oz (0.2 mm) on the long axis between the hole and theunsplit end of the specimen. The gage foot shall be adjacent to,but shall not overlap, the hole.8.2 Clamp one of the tongues on the specimen in each
11、 of thetesting grips so that the long axis of the tongue is in thedirection of the motion of the movable grip. The faces of thegrips shall be approximately 2 in. (50.8 mm) from the commonbase of the tongues (from the hole).8.3 Operate the machine at 10 6 2 in. (254 6 50.8 mm) perminute until the spe
12、cimen starts to tear. At the instant of theinitial tear, note and record the load registered by the machine.9. Report9.1 The thickness measurement of all specimens tested shallbe averaged to the nearest 0.5 oz (0.2 mm) and reported as thethickness of the sample.1This test method is under the jurisdi
13、ction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.07 Physical PropertiesCurrent edition approved April 1, 2005. Published May 2005. Originallyapproved in 1987. Last previous edition approved in 2000 as D 4704 00.2For referenced ASTM standards, visit the ASTM
14、website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
15、States.9.2 The load required to tear the specimens shall be aver-aged to the nearest pound and reported as the tongue tearstrength of the sample.9.3 The direction of the long axis of the specimen relative tothe backbone shall be reported.10. Precision and Bias (or Reproducibility)10.1 This test meth
16、od is adopted from the procedures 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 inter-laboratory test data is no longer available. Theuser is cautioned t
17、o verify by the use of reference materials, ifavailable, that the precision and bias (or reproducibility) of thistest method is adequate for the contemplated use.11. Keywords11.1 leather; tear strength; tearing strength; tongue tear;tongue tear strength; strengthASTM International takes no position
18、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 entirely their own responsibility.Th
19、is 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 standardsand should be addressed to ASTM Int
20、ernational 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 on Standards, at the address shown
21、 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 4704 00 (2005)2
