1、Designation: B258 14Standard 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 ad
2、option 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 Defe
3、nse.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 st
4、rengthsof 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 designat
5、ed 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 temperatur
6、e, 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 (With
7、drawn1990)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 C
8、opper 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
9、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-All
10、oy 6201-T81Wire 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 Int
11、ermediate 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 co
12、nsidered 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 a
13、pproved 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 ASTMSta
14、ndards 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 States14. Standard
15、 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
16、 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
17、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 rules and are given inTable 1 for convenient referenc
18、e (Explanatory Note 2).6. Standard Nominal Cross-Sectional Areas6.1 Standard nominal cross-sectional areas in circular milsand square millimetres shall be calculated in accordance withthe following equations and shall be rounded in accordancewith Section 4 to the same number of significant figures a
19、s usedin expressing the standard diameters, but in no case to less thanthree significant figures:Area, cmil 5 d2Area, mm25 d235.067 31024where:d = diameter of the wire in mils as given in Table 1.Standard nominal cross-sectional areas in circular mils andsquare millimetres have been calculated in ac
20、cordance with theforegoing rules and are given in Table 1 for convenientreference.7. Rules for Calculations Involving Mass and Length7.1 Standard nominal mass and lengths shall be calculatedfrom the standard wire diameters specified in Table 1,inaccordance with the following equations. They shall be
21、rounded in the final value only, in accordance with Section 4,to the same number of significant figures as used in expressingthe standard diameters, but in no case to less than threesignificant figures:W 5 d23 30.34049 31023L 5 1/d2! 3 1/! 32.9369 3106TABLE 1 Standard Nominal Diameters and Cross-Sec
22、tional Areas of AWG Sizes of Solid Round Wires at 20CSize Diameter Cross-Sectional Area Size Diameter Cross-Sectional AreaAWG mils mm cmils mm2AWG mils mm cmils mm24/0 460.0 11.684 211 600 107.2 29 11.3 0.287 128 0.06473/0 409.6 10.404 167 800 85.0 30 10.0 0.254 100 0.05072/0 364.8 9.26 133 100 67.4
23、 31 8.9 0.226 79.2 0.04011/0 324.9 8.25 105 600 53.5 32 8.0 0.203 64.0 0.03241 289.3 7.35 83 690 42.4 33 7.1 0.180 50.4 0.02552 257.6 6.54 66 360 33.6 34 6.3 0.160 39.7 0.02013 229.4 5.82 52 620 26.7 35 5.6 0.142 31.4 0.01594 204.3 5.19 41 740 21.1 36 5.0 0.127 25.0 0.01275 181.9 4.62 33 090 16.8 37
24、 4.5 0.114 20.2 0.01036 162.0 4.11 26 240 13.3 38 4.0 0.102 16.0 0.008117 144.3 3.67 20 820 10.6 39 3.5 0.0890 12.2 0.006218 128.5 3.26 16 510 8.37 40 3.1 0.0787 9.61 0.004879 114.4 2.91 13 090 6.63 41 2.8 0.0711 7.84 0.0039710 101.9 2.59 10 380 5.26 42 2.5 0.0635 6.25 0.0031711 90.7 2.30 8 230 4.17
25、 43 2.2 0.0559 4.84 0.0024512 80.8 2.05 6 530 3.31 44 2.0 0.0508 4.00 0.0020313 72.0 1.83 5 180 2.63 45 1.76 0.0447 3.10 0.0015714 64.1 1.63 4 110 2.08 46 1.57 0.0399 2.46 0.0012515 57.1 1.45 3 260 1.65 47 1.40 0.0356 1.96 0.00099316 50.8 1.29 2 580 1.31 48 1.24 0.0315 1.54 0.00077917 45.3 1.15 2 05
26、0 1.04 49 1.11 0.0282 1.23 0.00062418 40.3 1.02 1 620 0.823 50 0.99 0.0252 0.980 0.00049719 35.9 0.904 1 290 0.653 51 0.88 0.0224 0.774 0.00039220 32.0 0.813 1 020 0.519 52 0.78 0.0198 0.608 0.00030821 28.5 0.724 812 0.412 53 0.70 0.0178 0.490 0.00024822 25.3 0.643 640 0.324 54 0.62 0.0158 0.384 0.0
27、0019523 22.6 0.574 511 0.259 55 0.55 0.0140 0.302 0.00015324 20.1 0.511 404 0.205 56 0.49 0.0125 0.240 0.00012225 17.9 0.455 320 0.16226 15.9 0.404 253 0.12827 14.2 0.361 202 0.10228 12.6 0.320 159 0.0804B258 142where:W = mass, lb/1000 ft,d = diameter of the wire in mils as given in Table 1, = densi
28、ty of the wire material at 20C in g/cm3as givenin Table 2, andL = length, ft/lb.8. Rules for Calculations Involving Resistivity8.1 Standard nominal resistances and other values derivedfrom the resistivity units shall be calculated from the standardwire diameters specified in Table 1 in accordance wi
29、th thefollowing equations. All values so derived shall be rounded inthe final value only, in accordance with Section 4, to the samenumber of significant figures as used in expressing the standarddiameters, but in no case to less than three significant figures:D 2 c resistance at 20C, /1000 ft 5 /d23
30、 !# 3105.35D 2 c resistance at 20C, /lb 5 /23 d4!# 30.30940 3106Length at 20C, ft/ 5 d23 !/# 39.4924Mass at 20C, lb/ 5 23 d4!/# 33.2321 31026where:d = diameter of the wire in mils as given in Table 1, = resistivity of the wire material at 20C in lb/mile2asgiven in Table 2 (Explanatory Note 3), and =
31、 density of the wire material at 20C in g/cm3as given inTable 2.9. Rules for Calculating Rated Strength9.1 Standard rated strengths shall be calculated from thestandard wire diameters specified in Table 1 in accordance withthe following equation and shall be rounded in the final valueTABLE 2 Density
32、 and Resistivity of Electrical Conductor MaterialsMaterialDensity, ,at20C, g/cm3ResistivityA, ,at20C, lb/mile2 MaterialDensity,at20C, g/cm3Resistivity, ,at20C lb/mile2Copper (Specifications B1, B2, Aluminum-Clad Steel (Specification 6.59 3191B3, B33, B47 and B189), B415)Volume Conductivity, %IACS:Co
33、pper-Clad Steel (SpecificationB227):100 8.89 875.2097.66 8.89 896.15 Grade 30 HS 8.15 272897.16 8.89 900.77 Grade 30 EHS 8.15 272896.66 8.89 905.44 Grade 40 8.15 204596.16 8.89 910.15 Grade 40 EHS 8.15 204594.16 8.89 929.52 Galvanized Steel (Telephone and93.15 8.89 939.51 Telegraph) (SpecificationBr
34、onze (Specification B9): A111):Class A 8.89 2188 Class A Coating:Class B 8.89 1346 Grade EBB (Non-Copper 7.78 5000Class C 8.89 1094 Bearing)Copper Alloys (Specification Grade BB (Copper Bearing) 7.78 5800B105B): Grade BB (Non-Copper 7.78 5600Grade 8.5 8.78 10 169 Bearing)Grade 13 8.78 6649 Class B C
35、oating:Grade 15 8.54 5605 Grade EBB (Non-Copper 7.78 4900Grade 20 8.89 4376 Bearing)Grade 30 8.89 2917 Grade BB (Copper Bearing) 7.78 5600Grade 40 8.89 2188 Grade BB (Non-Copper 7.78 5450Grade 55 8.89 1591 Bearing)Grade 65 8.89 1346 Class C Coating:Grade 74 8.89 1183 Grade EBB (Non-Copper 7.78 4800G
36、rade 80 8.89 1094 Bearing)Grade 85 8.89 1030 Grade BB (Copper Bearing) 7.78 5400Aluminum, 1350 (Specifications Grade BB (Non-Copper 7.78 5300B230/B230M, B314, andB609/B609M),Bearing)Volume Conductivity, %IACS:Galvanized Steel (Telephone andTelegraph) (SpecificationA326):61.8 2.705 430.9161.2 2.705 4
37、35.1361.0 2.705 436.56 Class A Coating:Aluminum Alloys (Specifications Grade 85 7.83 5800B396 and B398/B398M) Class B Coating:Alloy 5005H19 2.70 496.84 Grade 135 7.83 6500Alloy 6201T81 2.69 504.43 Grade 85 7.80 5600Aluminum Alloy 8000 Series Grade 135 7.80 6300(Specification B800) Class C Coating:Vo
38、lume Conductivity, %IACS:Grade 85 7.77 540061.0 2.71 437.36 Grade 135 7.77 6100ATo convert from lb/mile2to g/m2divide by 5710.0. See Table 1 in Test Method B193.BVarious compositions are permitted for some of the grades in Specification B105 and the density value may not apply to all materials suppl
39、ied to this specification. Incase of doubt, the density value should be determined or obtained from the manufacturer.B258 143only, in accordance with Section 4, to the same number ofsignificant figures as used in expressing the standard diameters,but in no case to less than three significant figures
40、:Rated strength, lb 5 d23 T 30.7854 31026where:d = diameter of the wire in mils as given in Table 1, andT = tensile strength, psi, applicable to the wire material,temper, and size, for which reference should be made tothe specifications which cover the material.10. Tolerances10.1 The standard dimens
41、ions given in Table 1 and thecalculated values for mass, resistances, and rated strengthsobtained by the use of the formulas included in this specifica-tion are all nominal values. This specification is not concernedwith quantitative values of tolerances per se, but it is contem-plated that the stan
42、dard nominal wire dimensions specified inTable 1, and the properties derived therefrom, shall be madesubject to tolerances as indicated in either the individualspecifications applicable to the wires of various materials andtempers or as may be mutually agreed by the manufacturer andthe purchaser.EXP
43、LANATORY NOTESNOTE 1Except for certain classes of wire products, theAmerican WireGage (formerly known as the Brown or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).4NBS Handbook 100, Nat. Institute of Standards and Technology, , is sold by theNational Technical Information Service, 5285 Port Royal Road, Springfield, VA22161.B258 145
