ASTM_B_258_-_14.pdf

Designation:B25814Standard Specification forStandard Nominal Diameters and Cross-Sectional Areas ofAWG Sizes of Solid Round Wires Used as ElectricalConductors1This standard is issued under the fixed designation B258;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 specification prescribes standard nominal diam-eters and cross-sectional areas of American Wire Gage(AWG)sizes of solid round wires,used as electrical conductors,andgives equations and rules for the calculation of standardnominal mass and lengths,resistances,and breaking strengthsof such wires(Explanatory Note 1).1.2 The values stated in inch-pound or SI units are to beregarded separately as standard.Each system shall be usedindependently of the other.Combining values of the twosystems may result in nonconformance with the specification.For conductor sizes designated by AWG or kcmil sizes,therequirements in SI units have been numerically converted fromthe corresponding values stated or derived,in inch-pound units.For conductor sizes designated by SI units only,the require-ments are stated or derived in SI units.1.2.1 For density,resistivity and temperature,the valuesstated in SI units are to be regarded as standard.2.Referenced Documents2.1 ASTM Standards:2A111 Specification for Zinc-Coated(Galvanized)“Iron”Telephone and Telegraph Line WireA326 Specification for Zinc-Coated(Galvanized)High Ten-sile Steel Telephone and Telegraph Line Wire(Withdrawn1990)3B1 Specification for Hard-Drawn Copper WireB2 Specification for Medium-Hard-Drawn Copper WireB3 Specification for Soft or Annealed Copper WireB9 Specification for Bronze Trolley WireB33 Specification for Tin-Coated Soft or Annealed CopperWire for Electrical PurposesB47 Specification for Copper Trolley WireB105 Specification for Hard-Drawn Copper Alloy Wires forElectric ConductorsB189 Specification for Lead-Coated and Lead-Alloy-CoatedSoft Copper Wire for Electrical PurposesB193 Test Method for Resistivity of Electrical ConductorMaterialsB227 Specification for Hard-Drawn Copper-Clad Steel WireB230/B230M Specification for Aluminum 1350H19 Wirefor Electrical PurposesB314 Specification for Aluminum 1350 Wire for Communi-cation Cable(Withdrawn 1994)3B396 Specification for Aluminum-Alloy 5005-H19 Wire forElectrical Purposes(Withdrawn 2003)3B398/B398M Specification for Aluminum-Alloy 6201-T81and 6201-T83 Wire for Electrical PurposesB415 Specification for Hard-Drawn Aluminum-Clad SteelWireB609/B609M Specification for Aluminum 1350 RoundWire,Annealed and Intermediate Tempers,for ElectricalPurposesB800 Specification for 8000 Series Aluminum Alloy Wirefor Electrical PurposesAnnealed and Intermediate Tem-persE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsF205 Test Method for Measuring Diameter of Fine Wire byWeighing3.Standard Reference Temperature3.1 For the purpose of this specification,all wire dimensionsand properties shall be considered as occurring at the interna-tionally standardized reference temperature of 20C(68F).1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.02 onMethods of Test and Sampling Procedure.Current edition approved April 1,2014.Published April 2014.Originallyapproved in 1951.Last previous edition approved in 2008 as B258 02(2008).DOI:10.1520/B0258-14.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Standard Rules for Rounding4.1 All calculations for the standard nominal dimensionsand properties of solid round wires shall be rounded in the finalvalue only,in accordance with rounding method of PracticeE29.5.Standard Nominal Diameters5.1 Standard nominal diameters of AWG sizes of solidround wires shall be calculated in accordance with the conven-tional mathematical law of the American Wire Gage(seeExplanatory Note 1)and in accordance with Section 4.5.2 For wire sizes 4/0 to 44 AWG,inclusive,nominaldiameters shall be expressed in no more than four significantfigures but in no case closer than the nearest 0.1 mil(0.0001in.).5.3 For wire sizes 45 to 56 AWG,inclusive,nominaldiameters shall be expressed to the nearest 0.01 mil(0.00001in.).5.4 The standard nominal diameters expressed in mils havebeen calculated in accordance with these rul