ASTM_A_400_-_69_2012.pdf

Designation:A40069(Reapproved 2012)Standard Practice forSteel Bars,Selection Guide,Composition,and MechanicalProperties1This standard is issued under the fixed designation A400;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 U.S.Department of Defense.1.Scope1.1 This practice covers the selection of steel bars accordingto section and to the mechanical properties desired in the partto be produced.This is not a specification for the procurementof steel.Applicable procurement specifications are listed inSection 5.1.2 Several steel compositions intended for various sectionsand mechanical property requirements are presented in Tables1-6.The criteria for placing a steel composition in one of thethree general class designations,Classes P,Q,and R(describedin Section 4)are as follows:1.2.1 Classes P and Q should be capable of developing themechanical properties shown in Tables 1-4 by liquid quenchingfrom a suitable austenitizing temperature,and tempering at800F(427C)or higher.Ahardness indicated by tests made ata location shown in Fig.1,A,B,or C,is taken as evidence thata composition is capable of meeting other equivalent mechani-cal properties shown in the tables.Normal good shop practicesare assumed,with control of austenitizing and temperingtemperatures,and mild agitation of the part in the quenchingbath.1.2.2 Class R should be capable of developing the mechani-cal properties shown in Tables 5 and 6 as hot rolled,by colddrawing,or by cold drawing with additional thermal treatment.The locations for obtaining tension tests are described in 6.2.1.3 It is not implied that the compositions listed in the tablesare the only ones satisfactory for a certain class and mechanicalproperty requirement.Steels with lower alloy contents areoften satisfactory through the use of special processing tech-niques.1.4 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.2.Referenced Documents2.1 ASTM Standards:2A108 Specification for Steel Bar,Carbon and Alloy,Cold-FinishedA304 Specification for Carbon and Alloy Steel Bars Subjectto End-Quench Hardenability RequirementsA311/A311M SpecificationforCold-Drawn,Stress-Relieved Carbon Steel Bars Subject to Mechanical Prop-erty RequirementsA322 Specification for Steel Bars,Alloy,Standard GradesA633/A633M Specification for Normalized High-StrengthLow-Alloy Structural Steel PlatesA675/A675M Specification for Steel Bars,Carbon,Hot-Wrought,Special Quality,Mechanical Properties3.Significance and Use3.1 If the desired mechanical properties are as described in4.1.1 for material identified as Classes P-1 through P-7,or in4.1.2 for material identified as Classes Q-1 through Q-7,thestrength level desired can be based on hardness or theequivalent tensile or yield strength as shown in Tables 1-4.Ifthe desired mechanical properties are as set forth in 4.1.3 formaterial identified as Classes R-1 through R-6,the strengthlevel is based on yield strength as shown in Tables 5 and 6.3.2 The user,after determining the mechanical propertyrequirements of the critical section(that carrying the greateststress)of the part,should select the composition or composi-tions from Tables 1-6 that fulfills these requirements and ismost suitable for processing.4.Classification4.1 Steel bar compositions under this practice are classifiedaccording to mechanical property requirements and the criticalsection size of the part to be produced,as follows:4.1.1 Classes P-1 through P-7 comprise bars for parts tooperate under severe service conditions requiring high yield1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.15 on Bars.Current edition approved March 1,2012.Published April 2012.Originallyapproved in 1956.Last previous edition approved in 2006 as A400 69(2006).DOI:10.1520/A0400-69R12.2For 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 strength(90 000 psi(621 MPa)and over),good ductility,andrelatively high notch toughness.The applicable section sizes,identified as Classes P-1 through P-7,are shown in Table 7.The steel compositions suitable for Classes P-1 through P-7and for various desired mechanical properties are listed inTables 1 and 2.4.1.2 Classes Q-1 through Q-7 comprise bars fo