1、Designation: B 501 04Standard Specification forSilver-Coated, Copper-Clad Steel Wire for ElectronicApplication1This standard is issued under the fixed designation B 501; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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-coat
3、ed, round, copper-clad steel wire for electronic application.1.2 Silver coatings in mass percentages of the total mass ofthe coated wire are as follows: 1.25, 2.5, 4.0, 6.1, and 8.0.1.2.1 Silver-coated wire having different minimum percent-age of silver by mass may be obtained by mutual agreementbet
4、ween the manufacturer and the purchaser. For informationpurposes, the thickness of coating in microinches provided bythe mass percentages listed in 1.2 is shown in Table 1.1.3 Four classes of copper-clad steel wire are covered asfollows: Class 30HS nominal 30 % conductivity hard-drawn,Class 30A nomi
5、nal 30 % conductivity annealed, Class 40HSnominal 40 % conductivity hard-drawn, and Class 40A nomi-nal 40 % conductivity annealed.1.4 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only except for resistivity, where the SI
6、units are tobe regarded as the standard.1.5 The following safety hazards caveat pertains to the testmethod described in this specification. This standard does notpurport to address all of the safety problems, if any, associatedwith its use. It is the responsibility of the user of this standardto est
7、ablish appropriate safety and health practices anddetermine the applicability of regulatory limitations prior touse. (CautionConsideration should be given to toxicity andflammability when selecting solvent cleaners.)2. Referenced Documents2.1 The following documents of the issue in effect on dateof
8、material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:2B 193 Test Method for Resistivity of Electrical ConductorMaterialsB 258 Specification for Standard Nominal Diameters andCrossSectional Areas of AWG Sizes of Solid RoundWires Used as Electrical Cond
9、uctorsB 452 Specification for CopperClad Steel Wire for Elec-tronic Application3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 lotany amount of wire of one class and size pre-sented for acceptance at one time, such amount, however, notto exceed 10 000 lb (4500 kg) (Note 1).3.1
10、.2 samplea quantity of production units (coils, reels,and so forth) selected at random from the lot for the purpose ofdetermining conformance of the lot to the requirements of thisspecification.3.1.3 specimena length of wire removed for test purposesfrom any individual production unit of the sample.
11、NOTE 1A lot should comprise material taken from a product regularlymeeting the requirements of this specification. Inspection of individuallots of less than 500 lb (250 kg) of wire cannot be justified economically.For small lots of 500 lb (250 kg) or less, the purchaser may agree to themanufacturers
12、 regular inspection of the product as a whole as evidence ofacceptability of such small lots.4. Ordering Information4.1 Orders for material under this specification shall includethe following information:4.1.1 Quantity of each size,4.1.2 Wire size (see 7.1 and Table 1),4.1.3 Class of basis wire (see
13、 1.3),4.1.4 Mass percentage of coating (see 1.2 and Table 1),4.1.5 Package size (see Section 12),4.1.6 Special packaging marking, if required, and4.1.7 Place of inspection (see 9.1).1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsi
14、bility of Subcommittee B01.06 onComposite Conductors.Current edition approved Sept. 1, 2004. Published September 2004. Originallyapproved in 1969. Last previous edition approved in 1999 as B 509 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
15、at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Materials and Manufacture5.1 The basis materi
16、al shall consist of copper-clad steel wireconforming to the product description, quality and specifica-tion requirements of Specification B 452.5.2 The silver-coated wire shall consist of the basis wirecoated with silver. The quality of the silver-coated wire shall besuch that the finished product m
17、eets the properties and require-ments in this specification (Note 2).NOTE 2Silver coatings on copper-clad steel provide for:(a) A barrier between the copper and insulation whose curing tempera-ture in the process of fabricating is too high for the use of tin-coated wires.(b) A low contact resistance
18、 between the strands of outer conductors ofcoaxial conductors used in high-frequency circuits.(c) A low radio-frequency resistance of conductors used in high-frequency circuits (skin effect).(d) Good solderability for high-temperature hook-up wires whichprohibit the use of tin-coated wires due to hi
19、gh curing temperatures usedin fabricating the finished wire.6. General Requirements6.1 Tensile strength and elongation of the silver-coated wireshall conform to the requirements of Specification B 452 forthe applicable size and class of copper-clad steel wire.6.2 ResistivityThe electrical resistivit
20、y at a temperature of20C shall not exceed the values prescribed in Table 2. SeeNote 3 for calculating electrical resistance.6.3 Continuity of CoatingThe coating shall be continu-ous. The continuity of the coating shall be determined onrepresentative samples taken before stranding or insulating andsh
21、all be determined by the sodium polysulfide test, in accor-dance with 10.2.3.1. Wire whose coating mass corresponds toa thickness less than 0.00005 in. (50 in.) shall not be subjectto this test.6.4 Mass of CoatingThe mass of coating expressed inpercent of the total mass of the wire shall be not less
22、 than thepercentage specified and referred to in this specification or thepercentage as agreed on between the manufacturer and pur-chaser at the time of the placing of the order. For ease ofcomparison, the thickness of coating for various percentageshas been included in Table 1.6.5 JointsNecessary j
23、oints in the wire and rods prior tofinal coating and drawing shall be made in accordance withgood commercial practice. Joints made after coating shall notbe allowed to remain in the final product.NOTE 3Relationships which may be useful in connection with thevalues of electrical resistivity prescribe
24、d in this specification are shown inTable 2. Resistivity units are based on the International Annealed CopperStandard (IACS) adopted by IEC in 1913, which is158 Vmm2/m at 20Cfor 100 % conductivity. The values of 0.017241 Vmm2/m and the valueof 0.15328 Vg/m2at 20C are respectively the international e
25、quivalent ofTABLE 1 Silver Mass Percent and Thickness of CoatingDiameter Cross-Sectional Area at 20CThickness of Silver, in.(for information only)in. mm cmil in.2mm21.25%2.5%4.0%6.1%8.0%0.0720 1.829 5 180 0.00407 2.63 176 352 569 876 1 1580.0641 1.628 4 110 0.00323 2.08 156 313 507 779 1 0310.0571 1
26、.450 3 260 0.00256 1.65 139 279 451 694 9180.0508 1.290 2 580 0.00203 1.31 124 248 401 618 8170.0453 1.151 2 050 0.00161 1.04 111 222 358 551 7280.0403 1.024 1 620 0.00128 0.823 98 197 318 490 6480.0359 0.912 1 290 0.00101 0.653 88 176 284 437 5770.0320 0.813 1 020 0.000804 0.519 78 156 253 389 5150
27、.0285 0.724 812 0.000638 0.412 70 139 225 347 4580.0253 0.643 640 0.000503 0.324 62 124 200 308 4070.0226 0.574 511 0.000401 0.259 55 111 179 275 3630.0201 0.511 404 0.000317 0.205 49 98 159 244 3230.0179 0.455 320 0.000252 0.162 44 88 141 218 2880.0159 0.404 253 0.000199 0.128 39 78 126 193 2560.01
28、42 0.361 202 0.000158 0.102 35 69 112 173 2280.0126 0.320 159 0.000125 0.0804 31 62 100 153 2030.0113 0.287 128 0.000100 0.0647 28 55 89 137 1820.0100 0.254 100 0.0000785 0.0507 24 49 79 122 1610.0089 0.226 79.2 0.0000622 0.0401 22 44 70 108 1430.0080 0.203 64.0 0.0000503 0.0324 39 63 97 1290.0071 0
29、.180 50.4 0.0000396 0.0255 35 56 86 1140.0063 0.160 39.7 0.0000312 0.0201 31 50 77 1010.0056 0.142 31.4 0.0000246 0.0159 26 44 68 900.0050 0.127 25.0 0.0000196 0.0127 24 40 61 800.0045 0.114 20.2 0.0000159 0.0103 22 36 55 720.0040 0.102 16.0 0.0000126 0.00811 32 49 640.0035 0.089 12.2 0.00000962 0.0
30、0621 28 43 560.0031 0.079 9.61 0.00000755 0.00487 24 38 50TABLE 2 ResistivityResistivity, max at 20CClass of Wire Vmm2/m30HS and 30A 0.0586240HS and 40A 0.04397B501042volume and mass resistivity of annealed copper equal to 100 % conduc-tivity. The latter term means that a copper wire1minlength and m
31、ass of1 g would have a resistance of 0.15328 V. This is equivalent to aresistivity value of 875.20 Vlb/mile2, which signifies the resistance of acopper wire 1 mile in length with mass of 1 lb. It is also equivalent, forexample, to 1.7241 V/cm of length of a copper bar 1 cm2in cross section.A complet
32、e discussion of this subject is contained in NBS Handbook 100of the National Institute of Standards and Technology. The use of fivesignificant figures in expressing resistivity does not imply the need forgreater accuracy of measurement than that specified in Test MethodB 193. The use of five signifi
33、cant figures is required for completereversible conversion from one set of resistivity units to another.7. Dimensions and Permissible Variations7.1 The wire sizes shall be expressed as the diameter of thewire in decimal fractions of an inch to the nearest 0.0001 in.(0.003 mm) (Note 4). For diameters
34、 under 0.0100 in. (0.254mm), the wire shall not vary from the specified diameter bymore than 60.0001 in. (0.003 mm) and for diameters of 0.0100in. (0.254 mm) and over, the wire shall not vary from thespecified diameter by more than 61 %, expressed to thenearest 0.0001 in. (0.003 mm).NOTE 4The values
35、 of the wire diameters in Table 1 are given to thenearest 0.0001 in. and correspond to the standard sizes given in Specifi-cation B 258. The use of gage numbers to specify wires is not recognizedin this specification because of the possibility of confusion. An excellentdiscussion of wire gages and r
36、elated subjects is contained in NBSHandbook 1003of the National Institute of Standards and Technology.8. Workmanship, Finish, and Appearance8.1 The coating shall consist of a smooth, continuous layer,firmly adherent to the surface of the copper. The wire shall bebright and free from all imperfection
37、s not consistent with goodcommercial practice.9. Sampling9.1 The number of production units in a sample (Note 5)shall be as follows:9.2 For elongation, resistivity, and mass of coating determi-nations, the sample shall consist of four production units. Forcontinuity of coating determinations, the sa
38、mple shall consistof eight production units. From each unit, one test specimen ofsufficient length shall be removed for the performance of therequired test.9.3 For dimensional measurements and surface finish, thesamples shall consist of a quantity of production units shown inTable 3 under the headin
39、g “First Sample.”9.4 For packaging inspection (when specified by the pur-chaser at the time of placing the order), the sample shall consistof a quantity of production units shown in Table 4.NOTE 5Cumulative results secured on the product of a single manu-facturer indicating continued conformance to
40、the criteria, are necessary toensure an overall product meeting the requirements of this specification.The sample size and conformance criteria given for the various charac-teristics are applicable only to lots produced under these conditions.10. Test Methods10.1 For tensile strength, elongation, re
41、sistivity, dimen-sional measurement and the quality of the basis wire, the latestissue of Specification B 452 shall apply and the tests shall beperformed on the silver-coated wire (Note 6).NOTE 6It is known that the rate of loading during tension testingaffects the performance of the sample to a gre
42、ater or lesser extentdepending upon many factors. In general, tested values of tensile strengthare increased and tested values of elongation are reduced with increase ofspeed of the moving head of the testing machine. In the case of tests onsoft or annealed wire, however, the effects of speed of tes
43、ting are notpronounced. Tests of soft wire made at speeds of moving head whichunder no-load conditions are not greater than 12 in./min (300 mm/min) donot alter the final results of tensile strength and elongation determinationsto any practical extent. In the case of hard-drawn wire, these effects ar
44、epronounced when the speed of the moving head is excessive. It issuggested that tests be made at speeds of moving head which, underno-load conditions, are not greater than 3 in./min (76 mm/min), but in nocase at a speed greater than that at which correct readings can be made.10.2 Continuity of Silve
45、r Coating:10.2.1 Specimens:10.2.1.1 Length of SpecimensTest specimens shall eachhave a length of about 6 in. (150 mm). They shall be tagged ormarked to correspond with the coil, spool, or reel from whichthey were cut.10.2.1.2 Treatment of SpecimensThe specimens shall bethoroughly cleaned by immersio
46、n in a suitable organic solventsuch as benzene, ether, or trichlorethylene for at least 3 min;then removed and wiped dry with a clean, soft cloth. Thespecimens thus cleaned shall be kept wrapped in a clean, drycloth until tested. That part of the specimen to be immersed inthe test solution shall not
47、 be handled. Care shall be taken toavoid abrasion by the cut ends.10.2.2 Special Solutions:10.2.2.1 Sodium Polysulfide SolutionA concentrated so-lution shall be made by dissolving sodium sulfide crystals (cp)in distilled water until the solution is saturated at about 21C(70F), and adding sufficient
48、flowers of sulfur (in excess of 250g/L of solution) to provide complete saturation, as shown bythe presence in the solution of an excess of sulfur after thesolution has been allowed to stand for at least 24 h. The testsolution shall be made by diluting a portion of the concentratedsolution with dist
49、illed water to a specific gravity of 1.142 at15.6C (60F). The sodium polysulfide test solution shouldhave sufficient strength to blacken thoroughly a piece of cleanuncoated copper wire in 5 s. A portion of the test solution usedfor testing samples shall not be considered to be exhausteduntil it fails to blacken a piece of clean copper as describedabove (Note 7).NOTE 7It is important that the polysulfide solution be of propercomposition and strength at the time of test. A solution which is notsaturated with sulfur or which has been made from decom
