1、Designation: B298 07 B298 12Standard Specification forSilver-Coated Soft or Annealed Copper Wire1This standard is issued under the fixed designation B298; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 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 Department of Defense.1. Scope1.1 This specification covers silver-coated, soft or anne
3、aled, round copper wire, intended for use in electrical equipment, asfollows:1.1.1 Class AWire whose silver coating is at least 1.25 % of the total weight of the coated wire.1.1.2 Class BWire whose silver coating is at least 2.50 % of the total weight of the coated wire.1.1.3 Class CWire whose silve
4、r coating is at least 4.00 % of the total weight of the coated wire.1.1.4 Class DWire whose silver coating is at least 6.10 % of the total weight of the coated wire.1.1.5 Class EWire whose silver coating is at least 10.00 % of the total weight of the coated wire.1.2 Silver-coated wire having differe
5、nt minimum percentages of silver by weight may be obtained by mutual agreement betweenthe manufacturer and the purchaser. For information purposes the thickness of coating in microinches provided by the percentageslisted above is shown in Table 1 (Explanatory Note 1).1.3 The SI values of resistance
6、and density are to be regarded as standard. For all other properties values values stated ininch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units thatare provided for information purposes only.only and are not considered standar
7、d.1.3.1 ExceptionsThe SI values for density, resistivity, and volume are to be regarded as standard.1.4 The following precautionary caveat pertains only to the test method section of this specification:This standard does notpurport to address all of the safety concerns, if any, associated with its u
8、se. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specificprecautionary statements see 8.4.1.2 and Explanatory Note 2.2. Referenced Documents2.1 The following docum
9、ents of the issue in effect at the time of reference form a part of this specification to the extentreferenced herein:2.2 ASTM Standards:2B4B49 Specification Tough-Pitch Lake Copper-Refinery Shapesfor Copper Rod Drawing Stock for Electrical Purposes(Withdrawn 1981)B5 Specification for High Conductiv
10、ity Tough-Pitch Copper Refinery ShapesB193 Test Method for Resistivity of Electrical Conductor MaterialsB258 Specification for Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as ElectricalConductorsE50 Practices for Apparatus, Reagents, and Safety Considerations fo
11、r Chemical Analysis of Metals, Ores, and Related Materials3. Ordering Information3.1 Orders for material under this specification shall include the following information:3.1.1 Quantity of each size,3.1.2 Wire size, diameter in inches (see 5.3 and Table 1),1 This specification is under the jurisdicti
12、on of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on Conductorsof Copper and Copper Alloys.Current edition approved May 15, 2007Nov. 15, 2012. Published June 2007November 2012. Originally approved in 1955. Last previous edition approved in 1999
13、2007as B298 99B298 07.1. DOI: 10.1520/B0298-07.10.1520/B0298-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM we
14、bsite.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult pri
15、or editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.3 Class of coating (Section 1 and Tabl
16、e 1),3.1.4 Type of copper, if special (see 4.2),3.1.5 Place of inspection (see 9.1), and3.1.6 Packaging and Package Marking (Section 10).3.1.7 In addition supplementary requirements shall apply only when specified by the purchaser in the inquiry, contract, orpurchase order for direct procurement by
17、agencies of the U.S. Government (see S1, S2, and S3).4. Materials and Manufacture4.1 The material shall be silver-coated copper wire (Explanatory Note 2), of such quality and purity that the finished productshall have the properties and characteristics prescribed in this specification.NOTE 1The foll
18、owing specifications define copper suitable for use: SpecificationsSpecification B4B49 and B5.4.2 Copper of special qualities, forms, or types, as may be agreed upon between the manufacturer and the purchaser, and thatwill conform to the requirements prescribed in this specification may also be used
19、.5. General Requirements5.1 Tensile PropertiesThe silver-coated wire shall conform to the requirements for elongation prescribed in Table 1. Norequirements for tensile strength are specified. For wire whose nominal diameter is more than 0.001 in. (1 mil)(0.025 mm) greaterthan a size listed in Table
20、1, but less than that of the next larger size, the requirements of the next larger size shall apply.5.2 ResistivityThe electrical resistivity of the coated wire at a temperature of 20C shall not exceed 875.20 ohmslb/mile2.5.3 Dimensions and Permissible VariationsThe wire sizes shall be expressed as
21、the diameter of the wire in decimal fractionsof an inch to the nearest 0.1 mil (0.0001 in.)0.0001 in. (0.0025 mm) (Explanatory Note 3). The coated wire shall not vary fromthe specified diameter by more than the following amounts:TABLE 1 Tensile RequirementsDiameter,in.Area at 20C Elongationin 10 in.
22、,min, %Thickness of Coating, in. (For Information Only)cmils in.2 Class A, 1.25% Silver Class B, 2.50% Silver Class C, 4.00% Silver Class D, 6.10% Silver Class E, 10.00% Silver0.1285 16 510 0.01297 30 340 680 1 090 1 659 2 7200.1144 13 090 0.01028 30 303 605 970 1 477 2 4220.1019 10 380 0.008155 25
23、270 539 864 1 316 2 1570.0907 8 230 0.00646 25 240 480 768 1 171 1 9410.0907 8 230 0.00646 25 240 480 768 1 171 1 9410.0808 6 530 0.00513 25 214 428 684 1 043 1 7100.0720 5 180 0.00407 25 190 381 610 930 1 5240.0641 4 110 0.00323 25 170 339 542 828 1 3570.0571 3 260 0.00256 25 151 302 483 737 1 2090
24、.0508 2 580 0.00203 25 134 269 430 656 1 0750.0453 2 050 0.00161 25 120 240 383 585 9590.0403 1 620 0.00128 25 107 213 341 520 8530.0359 1 290 0.00101 25 95 190 304 464 7600.0320 1 020 0.000804 25 85 169 270 413 6770.0285 812 0.000638 25 75 151 241 368 6030.0253 640 0.000503 25 67 134 214 327 5360.0
25、226 511 0.000401 25 60 120 191 292 4780.0201 404 0.00317 20 53 106 170 260 4250.0179 320 0.000252 20 47 95 151 231 3790.0159 253 0.000199 20 42 84 135 205 3370.0142 202 0.000158 20 . 75 120 183 3010.0126 159 0.000125 20 . 67 107 163 2670.0113 128 0.000100 20 . 60 96 146 2390.0100 100 0.0000785 20 .
26、53 85 129 2120.0089 79.2 0.0000622 15 . 47 75 115 1880.0080 64.0 0.0000503 15 . 42 68 103 1690.0071 50.4 0.0000396 15 . . 60 92 1500.0063 39.7 0.0000312 15 . . 53 81 1330.0056 31.4 0.0000246 15 . . 47 72 1190.0050 25.0 0.0000196 15 . . 42 65 1060.0045 20.2 0.0000159 15 . . . 58 950.0040 16.0 0.00001
27、26 15 . . . 52 850.0035 12.2 0.00000962 15 . . . 45 740.0031 9.61 0.00000755 15 . . . 40 660.0028 7.84 0.00000616 10 . . . . 590.0025 6.25 0.00000491 10 . . . . 530.00220.00204.844.000.000003800.000003141010.4742 This value was corrected editorially to conform with Table X1.1.B298 122Nominal Diamete
28、r, in.Permissible Variations inDiameter, plus and minusUnder 0.0100 0.0001 in.(0.1 mil)0.0100 or over 1 %5.4 Continuity of CoatingThe coating shall be continuous. The continuity of the coating shall be determined on representativesamples taken before stranding or insulating and shall be determined b
29、y the sodium polysulfide test, in accordance with 8.4. Wirewhose coating weight corresponds to a thickness less than 40 in. (0.00004 in.) shall not be subject to this test (Explanatory Note4).5.5 Weight of CoatingThe weight of coating expressed in percent of the total weight of the wire shall be not
30、 less than 1.25 %for Class A; 2.50 % for Class B; 4.00 % for Class C; 6.10 % for Class D; and 10.00 % for Class E. When coatings other than theseclasses are required, the weight of the coating shall be not less than that specified. For ease of comparison, the thickness of coatingfor these classes ha
31、s been included in Table 1 (Explanatory Note 4).5.6 JointsNecessary joints in the wire and rods prior to final plating and drawing shall be made in accordance with the bestcommercial practice. Joints made after plating shall not be allowed to remain in the final product.5.7 FinishThe coating shall c
32、onsist of a smooth continuous layer, firmly adherent to the surface of the copper. The wire shallbe bright and free from all imperfections not consistent with the best commercial practice.6. Conformance Criteria (Explanatory Note 5)6.1 Any lot of wire, the samples of which comply with the conformanc
33、e criteria of this section, shall be considered as complyingwith the requirements of Section 5. Individual production units that fail to meet one or more of the requirements shall be rejected.Failure of a sample group from a lot to meet one or more of the following criteria shall constitute cause fo
34、r rejection of the lot.The conformance criteria for each of the prescribed properties given in Section 5 are as follows:6.1.1 ElongationThe lot shall be considered conforming if the elongation of each of the selected specimens is not less thanthe elongation value in Table 1.6.2 ResistivityThe electr
35、ical resistivity of each of the four specimens shall conform to the requirements of 5.2. Failure to meetthese requirements shall constitute failure to meet the resistivity conformance criterion.6.3 DimensionsThe dimensions of the first sample (Table 2) shall conform to the requirements of 5.3. If th
36、ere are no failures,the lot conforms to this requirement. If there are failures, but the number of these do not exceed the allowable defect number, c2(Table 2), for the respective number of units in the sample, a second sample equal to n2 shall be taken and the total defects of then plus n2 units sh
37、all not exceed the allowable defect number, c2. Failure to meet this requirement shall constitute failure to meetthe dimensional conformance criterion.6.4 Continuity of CoatingThe continuity of the coating of each of the eight specimens shall conform to the requirements of5.4. Failure of more than t
38、wo specimens shall constitute failure to meet the continuity criterion. If not more than two specimensfail to meet the continuity criteria, eight additional specimens from the lot shall be tested, all of which shall conform to thecontinuity criteria. However, any individual production unit, the spec
39、imen from which failed to meet the continuity criteria, shallbe rejected.6.5 Weight of CoatingThe weight of coating of each of the four specimens shall conform to the requirements of 5.5. Failureof more than one specimen shall constitute failure to meet the weight criteria. If only one specimen fail
40、s to meet the weight criteria,four additional specimens from the lot shall be tested, all of which shall conform to the weight criterion. However, any individualproduction unit, the specimen from which failed the weight criteria, shall be rejected.6.6 PackagingConformance to the packaging requiremen
41、ts specified by the purchaser shall be determined in accordance withTable 3. The number of units in the sample showing nonconformance to the requirements shall not exceed the allowable defectnumber, c, in Table 3. Failure to meet this requirement shall constitute failure to meet the packaging confor
42、mance criterion.TABLE 2 Sampling for Dimensional Measurements and Surface FinishNumber of Unitsin LotFirst Sample Second Sample AllowableNumber ofDefects inBoth Samplec2Number ofUnits inSample,n1AllowableNumber ofDefects inFirst Sample,c1Number ofUnits inSample,n2n1 + n21 to 14, incl All 0 . . .15 t
43、o 50, incl 14 0 . . .51 to 100, incl 19 0 23 42 1101 to 200, incl 24 0 46 70 2201 to 400, incl 29 0 76 105 3401 to 800, incl 33 0 112 145 4Over 800 34 0 116 150 4B298 1237. Density7.1 For the purpose of calculating weights, cross-sections, etc., the density of the copper shall be taken as 8.89 g/cm3
44、 (0.32117lb/in.3) at 20C (Explanatory Note 6). The density of silver shall be taken as 10.5 g/cm3(0.1 mil) (0.37933 lb/in.3).8. Test Methods8.1 Tensile Strength and Elongation:8.1.1 No test for tensile strength shall be required.8.1.2 The elongation of wire with a nominal diameter greater than 0.080
45、8 in. (2.052 mm) shall be determined as the permanentincrease in length due to the breaking of the wire in tension (see Explanatory Note 7). The elongation shall be measured betweengage marks placed originally 10 in. (242 mm) apart upon the test specimen and expressed in percent of the original leng
46、th.8.1.3 The elongation of wire whose with a nominal diameter is larger equal to or less than 0.0808 in. (2.052 mm) in diametershall be determined as the permanent increase in length, expressed in percent of the original length, due to the breaking of the wirein tension, measured between gage marks
47、placed originally 10 in. (254 mm) apart upon the test specimen (Explanatory (2.053 mm)Note 7). The elongation of wire whose nominal diameter is 0.0808 in. and under may be determined as described above or bymeasurements made between the jaws of the testing machine. When the latter method is used, me
48、asurements are made betweenthe jaws, the zero length shall be the distance between the jaws at the start of the tension test and be as near 10 in. as practicable,and the (254 mm) as practicable. The final length shall be the distance between the jaws at the time of rupture. The fracture shallbe betw
49、een gage marks, in the case of specimens so marked, or between the marks or jaws of the testing machine machine,depending on method used, and not closer than 1 in. (25.4 mm) to either gage mark or either jaw.8.2 ResistivityThe electrical resistivity of the material shall be determined in accordance with Test Method B193 (ExplanatoryNote 8). The purchaser may accept certification that the wire was drawn from rod stock meeting the International Standard forAnnealed Copper in lieu of resistivity tests on the finished wire.8.3 Dimensional Measu
