ASTM_B_647_-_10_2016.pdf

Designation:B64710(Reapproved 2016)Standard Test Method forIndentation Hardness of Aluminum Alloys by Means of aWebster Hardness Gage1This standard is issued under the fixed designation B647;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.1.Scope1.1 This test method covers the determination of indentationhardness of aluminum alloys with a Webster hardness gage,Model B.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.2.1 ExceptionThe values given in parentheses are forinformation only.NOTE1Two other models,Aand B-75,are in use,but are not coveredin this test method.Model A does not provide numerical values ofhardness and Model B-75 covers only a part of the range of interest foraluminum alloys.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:2E6 Terminology Relating to Methods of Mechanical TestingE10 Test Method for Brinell Hardness of Metallic MaterialsE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsThe definitions of terms relating to hard-ness testing appearing in Terminology E6 shall be consideredas applying to the terms used in this test method.4.Significance and Use4.1 The Webster hardness gage is portable and thereforeuseful for in situ determination of the hardness of fabricatedparts and individual test specimens for production controlpurposes.It is not as sensitive as Rockwell or Brinell hardnessmachines;see 10.2.4.2 This test method should be used only as cited inapplicable material specifications.5.Apparatus(Fig.1)5.1 The Webster hardness gage,Model B,consists of threemain parts:the frame,operating handle,and penetrator housingassembly.The penetrator housing assembly includes the prin-cipal working parts,including the penetrator,loading spring,adjusting nut,penetrator housing,housing key,return spring,and dial indicator.5.2 The indentor is a hardened steel truncated cone.5.3 The dial indicator is graduated from 1 to 20,and isactuated by the penetrator so that the higher the reading,thehigher is the hardness of the test material.5.4 The configuration of the Webster hardness gage is suchthat it is operated like a pair of pliers.5.5 The clearance between the penetrator and the anvil isabout 6 mm(14in.),limiting the thickness of sample that canbe tested.6.Test Parts or Specimens6.1 Any part or piece of material greater than 1 mm(0.04in.)in thickness and equal to or less than 6 mm(14in.)inthickness and with a clear flat area at an edge approximately 25by 25 mm(1 by 1 in.)in size is suitable for test.6.2 The surfaces shall be essentially parallel,smooth,clean,and free of mechanical damage.The test surface may be lightlypolished to eliminate scratches or die lines.6.3 The clear,flat area shall be such that there will be a cleardistance of at least 3 mm(18in.)from the edge of the part orspecimen.1This test method is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.05 onTesting.Current edition approved May 1,2016.Published May 2016.Originallyapproved in 1984.Last previous edition approved in 2010 as B647 10.DOI:10.1520/B0647-10R16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.4 Parts or specimens with a slight taper or curvature mayalso be tested if a round anvil is used,as described in 8.1.1 andFig.2.7.Calibration7.1 Zero Adjustment:7.1.1 Operate the instrument against the bare anvil and notewhether or not the indicator gives the zero(full-scale)reading.7.1.2 A correction in zero reading is normally not neededexcept for one of the reasons listed below:7.1.2.1 A new penetrator has been installed,7.1.2.2 The dial indicator is changed from one instrument toanother,or7.1.2.3 Excessive wear has taken place.7.1.3 If an adjustment in zero is needed,turn the zeroadjustment screw below the indicator dial slowly(Fig.3),while operating the tester against the bare anvil and maintain-ing handle pressure,until the hand of the dial indicator rests onthe zero lin