ASTM_D_2941_-_13.pdf

Designation:D294113Standard Test Method forMeasuring Break Pattern of Leather(Break Scale)1This standard is issued under the fixed designation D2941;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.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 covers the measurement of the breakpattern of shoe upper leather using an arbitrary break scale.This test method does 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 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1517 Terminology Relating to LeatherD1610 Practice for Conditioning Leather and Leather Prod-ucts for Testing2.2 MIL Standard:3MIL-STD 663 Visual Inspection Guide for Footwear UpperLeather3.Terminology3.1 Definitions:3.1.1 break(of leather)the pattern of wrinkles formed onthe grain surface of upper leather when it is bent grain in toform a concave surface.This characteristic is observed in thevamp of the shoe in walking.For this reason this test methodis primarily intended for evaluation of cut parts.3.2 For definitions of other terms used in this test method,refer to Terminology D1517.4.Significance and Use4.1 Break depends on the fiber structure and on the relationbetween the grain and other strata of the leather.A fine break,or a grain pattern which shows many fine wrinkles when it isbent to form a concave surface,as it is in the vamp of a shoe,reflects favorably upon appearance and serviceability.A coarsebreak,on the other hand,where a few coarse wrinkles areformed on bending the grain to form a concave surface mayindicate that the grain layer is separating from the corium ormain stratum as in pipey leather.Shoes made from fine-breakleather are more attractive and tend to wear longer than shoesmade from coarse-break leather.(See MIL-STD 663 and theALCA Journal).45.Apparatus5,65.1 Satra Mandrel,consisting of two windows or hollows.5.2 Satra Visual Break Scale,consisting of eight levels ofbreak ranging from 1,fine,to 8,coarse.6.Test Specimen6.1 The sample for the test should be taken from an agreedarea of the hide,and shall be a piece of leather 2 by 4 in.(51by 102 mm)with the long dimension perpendicular to thebackbone;or a cut shoe part.6.2 Unless otherwise specified,one specimen shall be testedfrom each sample.7.Conditioning7.1 All specimens shall be conditioned according to PracticeD1610.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.03 on Footwear.This testmethod was developed in cooperation with the American Leather Chemists Assn.(Standard Method E64 1972).Current edition approved May 1,2013.Published May 2013.Originallyapproved in 1970.Last previous edition approved in 2012 as D2941 00(2012).DOI:10.1520/D2941-13.2For 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 page onthe ASTM website.3Available from Standardization Documents Order Desk,DODSSP,Bldg.4,Section D,700 Robbins Ave.,Philadelphia,PA 19111-50984Bailey,M.,Journal of the American Leather Chemists Association,JALCA,Vol 53,1958,p.568.5Landmann,A.W.,and Thompson,R.S.,Journal of the Society of LeatherTrades Chemists,JSLTC,Vol 47,1963,p.429.6The sole source of supply of the Satra mandrel and visual break scale knownto the committee at this time is the Shoe and Allied Trades Research Assn.,Kettering,England.If you are aware of alternative suppliers,please provide thisinformation to ASTM Headquarters.Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 8.Procedure8.1 With long dimension of the specimen parallel to thelength of the mandrel,bend it with thumb and fingers to bringit into contact with the outside of the mandrel,and observe thewrinkles through the windows.8.2 Compare the wrinkle pattern of the specimen with thoseof the Satra break scale.8.3 The specimen should be rated to the nearest12-grade,that is,if it appears that the break is better than 4 but not asgood as 3,the break of the leather should be graded as 312.Thu