1、Designation:D483100(Reapproved 2020)Standard Test Method forBuckle Tear Strength of Leather1This standard is issued under the fixed designation D4831;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number
2、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 on all types ofleather t
3、o determine the load required to tear a leather strapfastened in a buckle.This test method does not apply to wetblue.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlya
4、nd 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 practices and deter-mine the applicability of regulator
5、y 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 Recom-mendations issued by the World Trade Organiz
6、ation TechnicalBarriers to Trade(TBT)Committee.2.Significance and Use2.1 This test method is designed to measure the loadrequired to tear a leather strap fastened in a buckle.Tanners andleather buyers have found that this test gives an indication ofthe resistance of leather to tearing.2.2 This test
7、method should be suitable for specificationacceptance,designpurposes,manufacturingcontrol,development,and research.The thickness of the specimen anddirection of tear relative to the backbone will affect theuniformity of the test results.This test method may not applywhen the conditions of the test e
8、mployed differ widely fromthose specified in this test method.3.Apparatus3.1 Gauge,spring-type,for measuring thickness of units,graduated in 0.5 oz or 0.1 mm having a flat pressure foot 0.4 60.025 in.(10.2 6 0.6 mm)in diameter and a flat anvil 0.4 60.025 in.in diameter.The spring shall exert a force
9、 of 1 lbf(4.45 N)on the foot when the gauge reads 2 oz and 2 lbf(8.9N)when the gauge reads 12 oz.3.2 Steel Punch,which will make a316in.(4.8 mm)diameter hole.3.3 Harness Buckle,1.25 in.(4.7 mm)with a 0.175 60.005-in.(4.4 6 0.1-mm)diameter tongue.It shall be attachedto a strong strap,1.25 in.wide and
10、 at least 5 in.(127 mm)long.The strap shall be equipped with a keeper located approxi-mately 0.75 in.(19 mm)from the buckle.3.4 Testing Machine,power-driven.The applied load shallbe indicated on a dial,scale,or chart.The load indicator shallrecord or indicate the maximum load at the time of rupture
11、ofthe specimen.The machine shall be equipped with a set ofgrips for clamping the specimens.The faces of the grips shouldbe knurled or otherwise roughened to prevent slipping of thespecimen.The gripping surfaces shall be at least 1 by 112in.(25.4 by 38 mm).The grips shall be mounted with the longerdi
12、mension perpendicular to the direction of the application ofthe load.The speed of the power-activated grip shall be auniform speed of 10 6 2 in.(254 6 50 mm)/min when runningfree.The error of the machine up to a load of 50 lbf(222 N)shall not exceed 2%;at loads of more than 50 lbf the errorshall not
13、 exceed 1%.4.Sampling,Test Specimens,and Test Units4.1 The specimen shall be a piece of leather 1 by 8 in.(25by 200 mm).Note the direction of the long axis relative to thebackbone.5.Procedure5.1 Punch a316-in.(4.76-mm)hole on the long axis of thespecimen 3 in.(76.2 mm)from one end.5.2 Measure the th
14、ickness of the specimen to the nearest 0.5oz(0.2 mm)of the long axis between the hole and the shortend.Place the gauge foot adjacent to,but not overlapping,thehole.5.3 Fit the specimen in the buckle with the tongue of thebuckle in the hole and the short end of the specimen under thekeeper.Clamp the
15、other end of the specimen in one of the1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.01 on Vegetable Leather.Current edition approved Dec.1,2020.Published December 2020.Originallyapproved in 1988.Last previous edition
16、 approved in 2016 as D4831 00(2016).DOI:10.1520/D4831-00R20.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard 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.1testing machine g
