1、Designation: B 738 03Standard Specification forFine-Wire Bunch-Stranded and Rope-Lay Bunch-StrandedCopper Conductors for Use as Electrical Conductors1This standard is issued under the fixed designation B 738; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers bare bunch-stranded and rope-lay bunch-stranded condu
3、ctors made from round copper wiresfiner than No. 40 AWG with diameters less than 0.0031 in.(.078 mm), either coated or uncoated with tin or silver, for useas electrical conductors. (Explanatory Note 1).1.2 The values (SI units) for density and temperature areregarded as the standard. For all other p
4、roperties the inch-pound values are to be regarded as standard, and the SI unitsmay be approximate.2. Referenced Documents2.1 ASTM Standards:B 33 Specification for Tinned Soft or Annealed CopperWire for Electrical Purposes2B 49 Specification for Copper Rod Drawing Stock forElectrical Purposes3B 172
5、Specification for Rope-Lay Stranded Copper Con-ductors Having Bunch-Stranded Members, for ElectricalConductors2B 174 Specification for Bunch-Stranded Copper Conduc-tors for Electrical Conductors2B 193 Test Method for Resistivity of Electrical ConductorMaterials2B 258 Specification for Standard Nomin
6、al Diameters andCross-Sectional Areas of AWG Sizes of Solid Round WiresUsed as Electrical Conductors2B 298 Specification for Silver-Coated Soft or AnnealedCopper Wire2B 354 Terminology Relating to Uninsulated Metallic Elec-trical Conductors23. Classification3.1 For the purposes of this specification
7、, the followingclassifications have been assigned (Explanatory Note 2):3.1.1 Type:3.1.1.1 Type BBunch-stranded conductors.3.1.1.2 Type RRope-lay bunch-stranded conductors.3.1.2 Class:3.1.2.1 Class RStranded conductors using wire 42 AWG(0.0025).3.1.2.2 Class SStranded conductors using wire 44 AWG(0.0
8、020).3.1.2.3 Class TStranded conductors using wire 46 AWG(0.00157).3.1.2.4 Class UStranded conductors using wire 48 AWG(0.00124).3.1.2.5 Class VStranded conductors using wire 50 AWG(0.00099).3.2 Detailed information on Type B Conductors is found inTable 1 and Table 2. Detailed information on Type R
9、Conduc-tors is found in Table 3 and Table 2.4. Ordering Information4.1 Orders for materials under this specification shall in-clude the following information:4.1.1 Quantity of each size, class, and type,4.1.2 Conductor sizecircular-mil area, dc resistance (7.1)or AWG (5.2.1),4.1.3 Class and type (Se
10、ction 3),4.1.4 Whether coated or uncoated; if coated, designate typeof coating (6.1); if silver coated, the minimum thickness ofsilver (6.1.2), and whether tarnish protection is desired (11.3),4.1.5 Maximum length of lay (5.2.4), if required,4.1.6 Temper (6.2),4.1.7 Separators, if required (5.2.2),4
11、.1.8 Package size (11.1),4.1.9 Special package marking, if required (Section 10), and4.1.10 Place of inspection (Section 9).4.2 In addition, Supplementary Requirements shall applyonly when specified by the purchaser in the inquiry, contract, orpurchase order for direct procurement by agencies of the
12、 U.S.Government.1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.04 onConductors of Copper and Copper Alloys.Current edition approved October 1, 2003. Published October 2003. Originallyapproved in 1984. L
13、ast previous edition approved in 1998 as B 738 98.2Annual Book of ASTM Standards, Vol 02.03.3Annual Book of ASTM Standards, Vol 02.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Materials and Manufacture5.1 The material shall
14、be copper of such quality and puritythat the finished product shall have the properties and charac-teristics described in this specification. Material meeting therequirements of Specification B 49 is such a material.5.2 Construction:5.2.1 Cross-Sectional AreaThe cross-sectional area, num-ber, and di
15、ameter of wires for a variety of strand constructionsin general use are shown in Table 2.5.2.2 SeparatorsIf a separator is required to be furnishedwith the conductor, it shall be specified by the purchaser at thetime of the order as to the requirements for the kind andthickness of material and its a
16、pplication details.5.2.3 Joints:5.2.3.1 Necessary joints in wires shall be made in accor-dance with accepted commercial practice.5.2.3.2 Joints shall be so constructed and so disposedthroughout the conductor that the diameter or configuration ofthe completed conductor is not substantially affected,
17、and thatthe flexibility of the completed conductor is not adverselyaffected.5.2.4 Lay:5.2.4.1 Conductors of the same size and description fur-nished on one order shall have the same lay.5.2.4.2 The direction of the lay of bunch-stranded conduc-tors shall be at the option of the manufacturer unless o
18、therwisespecified by the purchaser.5.2.4.3 Unless otherwise specified by the purchaser, thelength of the lay of bare or coated bunch-stranded conductorsshall conform to the requirements of Table 4.5.2.4.4 The direction of the lay of the outer layer of rope-laystranded conductors shall be lefthand, u
19、nless otherwise speci-fied by the purchaser.5.2.4.5 The length of the lay of the outer layer of rope-laystranded conductors shall be not less than 8 or more than 16times the outside diameter of the completed conductor. Thelength of the lay of the wires composing the bunch-strandedmembers shall be no
20、t more than 30 times the diameter of themember.6. Physical Properties6.1 Wire CoatingWhen coated, the coating of the wires ofthe stranded conductor, before stranding, shall conform to therequirements of 6.1.1 or 6.1.2.6.1.1 Tin coating shall conform to the coating requirementsof Specification B 33.6
21、.1.2 Silver coating shall conform to the minimum thick-ness requirements of the purchase document. Minimum thick-ness shall be determined using the method for determiningplating thickness described in Specification B 298.6.1.3 The finished diameter and mass of the coated wiresused shall be substanti
22、ally equal to those of the uncoated wiresof the same class.6.2 TemperUnless otherwise specified, all coated conduc-tors shall be furnished in the annealed temper. Uncoatedconductors may be furnished either annealed or unannealed asordered (see 4.1.6).NOTE 1The term unannealed as used in this specifi
23、cation meanscold-worked conductor as produced on commercial wire-drawing ma-chines.6.3 Tensile Strength and ElongationThe stranded conduc-tor, in its finished form, shall conform to the following:Tensile Strength, min. Elongation, min,Finished State psi MPa 10 in. %UnannealedAnnealed40 000.275.107.
24、Electrical Properties7.1 DC ResistanceThe dc resistance in V/1000 ft of thebunch-stranded conductor shall not exceed the appropriatevalues specified in Table 5. The dc resistance in V/1000 ft ofthe rope-lay bunch-stranded conductor shall not exceed theappropriate values specified in Table 6 (Explana
25、tory Note 3and Note 4).8. Test Methods8.1 CoatingTests to determine conformance of the coat-ing to the requirements of Specification B 33 or SpecificationB 298 shall be performed on the individual wires beforestranding (see 6.1.1 to 6.1.3).8.2 Tensile Strength and Elongation:8.2.1 Tests to determine
26、 conformance to the tensile strengthand elongation requirements of 6.3 shall be made on thefinished stranded conductor.8.2.2 Determine tensile strength, Ts, expressed in poundsper square inch as follows:Ts5LAwhere:L = maximum load on the stranded conductor during thetension test (see Explanatory Not
27、e 5), lbs, andA = original cross-sectional area of the stranded conductor,in.2/in. (see 8.2).8.2.3 The original cross-sectional area of the stranded con-ductor shall be considered to be the cross-sectional area of theindividual wire calculated from the nominal wire diameter (seeTable 5) multiplied b
28、y the number of wires in the strandedconductor (Explanatory Note 6).8.2.4 Determine the elongation of the specimen as thepermanent increase in length, expressed in percent of theoriginal length, due to the breaking of the specimen in tension,by measurements made between the jaws of testing machine.T
29、he zero length shall be the distance between the jaws at thestart of the tension test, and shall be as near 10 in. (250 mm)as practicable. The final length shall be the distance betweenTABLE 1 Classification of Type B Bunch-Stranded ConductorsClass Wire Diameter, in.AConductor Sizes, AWGR 0.0025 (No
30、. 42 AWG) 24,26,28,30,32,34S 0.0020 (No. 44 AWG) 26,28,30,32,34,36T 0.00157 (No. 46 AWG) 28,30,32,34,36,38U 0.00124 (No. 48 AWG) 30,32,34,36,38,40V 0.00099 (No. 50 AWG) 32,34,36,38,40ASufficient quantities of wires of these diameters shall be used to formconductors having cross-sectional areas appro
31、ximately equal to the AWG conduc-tor sizes listed.B738032the jaws at the time of rupture. The fracture shall be betweenthe jaws of the testing machine and not closer than 1 in. (25mm) to either jaw.8.3 ElectricalTests to determine conformance to the elec-trical resistance requirements of 7.1 shall b
32、e made on thefinished stranded conductor in accordance with Test MethodB 193 (Explanatory Note 3).8.4 Other RequirementsFor the purpose of calculatingmass, cross-sectional area, and so forth, the density of thecoated copper shall be taken as 8.89 g/cm3(0.32117 lb/in.3)at20C (Explanatory Note 5).8.5
33、Examination for Workmanship of Finished UninsulatedStranded ConductorA visual inspection with the unaided eyeshall be performed on the outer layer of the conductor on thesupplied package. Use a white card (as a background) toascertain if any base metal is exposed through a break in thecoating. Detec
34、tion of any base metal constitutes rejection.8.6 Examination for Workmanship of Finished UninsulatedStranded ConductorA visual inspection with 103 magnifi-cation and a white background shall be performed on aconductor sample taken from the top of the supplied spool. Thesample shall be a minimum of 1
35、2 in. (30 cm) in length. Theouter surface of all stranded constructions shall be examined.Detection of excessive exposed base metal due to thestranding process, such as indications along one side of thesample due to excessive localized abrasion during stranding,constitutes rejection. Continuous line
36、s or patterns of exposedbase metals constitute rejection. Small, random point failuresshall not be cause for rejection.9. Inspection9.1 Unless otherwise specified in the contract or purchaseorder, the manufacturer shall be responsible for the perfor-mance of all inspection and test requirements spec
37、ified.9.2 All inspection and tests shall be made at the place ofmanufacture unless otherwise especially agreed upon betweenthe manufacturer and the purchaser at the time of purchase.9.3 The manufacturer shall afford the inspector representingthe purchaser all reasonable manufacturers facilities to s
38、atisfyhim that the material is being furnished in accordance with thisspecification.10. Product Marking10.1 The net mass, length (or lengths, and number oflengths, if more than one length is included in the package),size designation, type of conductor, purchase order number,and any other marks requi
39、red by the purchase order shall bemarked on a tag attached to the reel and, optionally, to the endof the conductor inside of the package. The same information,together with the manufacturers serial number, if any, and allshipping marks required by the purchaser, shall appear on theoutside of each pa
40、ckage.11. Packaging11.1 Package sizes for conductors shall be agreed upon bythe manufacturer and the purchaser in the placing of individualorders.11.2 The conductors shall be protected against damage inordinary handling and shipping.11.3 When specified, silver-plated wire shall be protectedfrom tarn
41、ish.TABLE 2 Construction Requirements of Bunch-Stranded and Rope-Lay Bunch-Stranded ConductorsANominalArea,cmilSize,AWGCLASS R CLASS S CLASS T CLASS U CLASS VMinimum Numberof Wires 0.0025 in.in Diameter(No. 42 AWG)Minimum Numberof Wires 0.0020 in.in Diameter(No. 44 AWG)Minimum Numberof Wires 0.00157
42、 in.in Diameter(No. 46 AWG)Minimum Numberof Wires 0.00124 in.in Diameter(No. 48 AWG)Minimum Numberof Wires 0.00099 in.in Diameter(No. 50 AWG)TypeBB TypeCR Type B Type R Type B Type R Type B Type R Type B Type R2580 16 . . . 665 . . . . . .1620 18 . . . 413 . . . . . .1020 20 . 168 . 259 . . . . . .6
43、40 22 . 105 . 168 . . . . . .404 24 65 . . 105 . 168 . . . .253 26 41 . 65 . . 105 . 168 . .159 28 26 . 40 . 65 . . 105 . 168100 30 16 . 25 . 40 . 65 . . 10564 32 10 . 16 . 25 . 40 . 65 .40 34 7 . 10 . 16 . 25 . 40 .25 36 . . 7 . 10 . 16 . 25 .16 38 . . . . 7 . 10 . 16 .10 40 . . . . . . 7 . 10 .ATh
44、is table shows a variety of strand constructions useful and generally adequate to meet the needs encountered. It is not intended that the constructions listed in thistable be exclusive of other constructions that may appear durable in certain applications employing the same number of wires. The cons
45、tructions shown in this table providefor a finished, noncovered, stranded conductor approximately of the area indicated. When specified by the purchaser, usually to provide additional area to compensatefor draw-down during subsequent processing, the number or size of wires composing the uncovered co
46、nductor may be increased as required.BType B Bunch-Stranded Conductors.CType R Rope-Lay Bunch-Stranded Conductors.TABLE 3 Classification of Type R Rope-Lay Bunch-StrandedConductorsAClass Wire Diameter, in.BConductor Sizes, AWGR 0.0025 (No. 42 AWG) 20,22S 0.0020 (No. 44 AWG) 16,18,20,22,24T 0.00157 (
47、No. 46 AWG) 24,26U 0.00124 (No. 48 AWG) 26,28V 0.00099 (No. 50 AWG) 28,30ARope-lay bunch-stranded conductors 7 by bunch-stranded members.BSufficient quantities of wires of these diameters shall be used to formconductors having cross-sectional areas approximately equal to the AWG conduc-tor sizes lis
48、ted.B73803312. Keywords12.1 copper electrical conductor; electrical conductor; elec-trical conductorcopper; fine-wire bunch-stranded conductor;rope-lay bunch-stranded conductor; stranded conductorTABLE 4 Maximum Length of Lay for Bunch-Stranded ConductorsSize, AWGNominal Diameter Nominal Area Maximu
49、m Length of Layin. (mm) cmil (mm2) in. (mm)24 0.024 (0.61) 404 (0.20) 0.70 (18)26 0.019 (0.48) 253 (0.13) 0.60 (15)28 0.015 (0.38) 159 (0.081) 0.50 (13)30 0.012 (0.30) 100 (0.051) 0.40 (10)32 0.009 (0.23) 64 (0.032) 0.30 (7.6)34 0.007 (0.18) 40 (0.020) 0.25 (6.4)36 0.006 (0.15) 25 (0.013) 0.20 (5.1)38 0.005 (0.13) 16 (0.0081) 0.15 (3.8)40 0.004 (0.10) 10 (0.0051) 0.13 (3.3)TABLE 5 DC Ohmic Resistance Per 1000 Ft. of Type B Bunch-Stranded ConductorsSize DesignationsConductor ConstructionACalculated TotalCross-SectionalArea cmilDC Resistance at 20C, V/1000 ft, m
