1、Designation: B501 10Standard Specification forSilver-Coated, Copper-Clad Steel Wire for ElectronicApplication1This standard is issued under the fixed designation B501; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 Department of Defense.1. Scope1.1 This specification covers silver-coated,
3、 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 agreementbetwee
4、n 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 nominal
5、 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 standard. The values given in parentheses are mathematicalconversions to SI units that are provided for inform
6、ation onlyand are not considered standard.1.4.1 ExceptionIn resistivity the SI units are to be re-garded as the standard1.5 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, ass
7、ociatedwith its use. It is the responsibility of the user of this standardto establish 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. R
8、eferenced Documents2.1 The following documents of the issue in effect on dateof material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:2B193 Test Method for Resistivity of Electrical ConductorMaterialsB258 Specification for Nominal Diameters and Cross-S
9、ectional Areas of AWG Sizes of Solid Round Wires Usedas Electrical ConductorsB452 Specification for Copper-Clad 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 ti
10、me, such amount, however, notto exceed 10 000 lb (4500 kg) (Note 1).3.1.2 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 remo
11、ved for test purposesfrom any individual production unit of the sample.NOTE 1Alot 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 o
12、f 500 lb (250 kg) or less, the purchaser may agree to themanufacturers 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 siz
13、e,4.1.2 Wire size (see 7.1 and Table 1),4.1.3 Class of basis wire (see 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, and1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Con
14、ductors and is the direct responsibility of Subcommittee B01.06 onComposite Conductors.Current edition approved April 1, 2010. Published May 2010. Originallyapproved in 1969. Last previous edition approved in 2004 as B501 04. DOI:10.1520/B0501-10.2For referenced ASTM standards, visit the ASTM websit
15、e, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States
16、.4.1.7 Place of inspection (see 9.1).5. Materials and Manufacture5.1 The basis material shall consist of copper-clad steel wireconforming to the product description, quality and specifica-tion requirements of Specification B452.5.2 The silver-coated wire shall consist of the basis wirecoated with si
17、lver. The quality of the silver-coated wire shall besuch that the finished product meets 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
18、fabricating is too high for the use of tin-coated wires.(b) A low contact resistance 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 fo
19、r high-temperature hook-up wires whichprohibit the use of tin-coated wires due to high 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 B452 for theapplicabl
20、e size and class of copper-clad steel wire.6.2 ResistivityThe electrical resistivity 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 shal
21、l be determined onrepresentative samples taken before stranding or insulating andshall 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
22、mass of coating expressed inpercent of the total mass of the wire shall be not less 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 o
23、f coating for various percentageshas been included in Table 1.6.5 JointsNecessary joints 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 w
24、hich may be useful in connection with thevalues of electrical resistivity prescribed in this specification are shown inTable 2. Resistivity units are based on the International Annealed CopperTABLE 1 Silver Mass Percent and Thickness of CoatingDiameter Cross-Sectional Area at 20CThickness of Silver,
25、 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 1.450 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
26、 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 5150.0285 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 0.00
27、0401 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 2560.0142 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
28、 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 0.180 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
29、 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 0.00621 28 43 560.0031 0.079 9.61 0.00000755 0.00487 24 38 50TABLE 2 ResistivityResistivity, max at 20CClass of Wire Vmm2/m
30、30HS and 30A 0.0586240HS and 40A 0.04397B501 102Standard (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 equivalent ofvolume and mass resistivity of annealed copper eq
31、ual to 100 % conduc-tivity. The latter term means that a copper wire1minlength and mass 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,
32、forexample, to 1.7241 V/cm of length of a copper bar 1 cm2in cross section.A complete 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 accu
33、racy of measurement than that specified in Test Method B193.The use of five significant figures is required for complete reversibleconversion 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 decim
34、al fractions of an inch to the nearest 0.0001 in.(0.003 mm) (Note 4). For diameters 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 diamete
35、r by more than 61 %, expressed to thenearest 0.0001 in. (0.003 mm).NOTE 4The values of the wire diameters in Table 1 are given to thenearest 0.0001 in. and correspond to the standard sizes given in Specifi-cation B258. The use of gage numbers to specify wires is not recognizedin this specification b
36、ecause of the possibility of confusion. An excellentdiscussion of wire gages and related 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
37、 the surface of the copper. The wire shall bebright and free from all imperfections 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
38、 consist of four production units. Forcontinuity of coating determinations, the sample 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, thesample
39、s shall consist of a quantity of production units shown inTable 3 under the heading “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 sec
40、ured on the product of a single manu-facturer indicating continued conformance to 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 produce
41、d under these conditions.10. Test Methods10.1 For tensile strength, elongation, resistivity, dimen-sional measurement and the quality of the basis wire, the latestissue of Specification B452 shall apply and the tests shall beperformed on the silver-coated wire (Note 6).NOTE 6It is known that the rat
42、e of loading during tension testingaffects the performance of the sample to a greater 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. I
43、n the case of tests onsoft or annealed wire, however, the effects of speed of testing 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 determ
44、inationsto any practical extent. In the case of hard-drawn wire, these effects arepronounced 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
45、 greater than that at which correct readings can be made.10.2 Continuity of Silver 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
46、.2.1.2 Treatment of SpecimensThe specimens shall bethoroughly cleaned by immersion in a suitable organic solventfor at least 3 min; then removed and wiped dry with a clean,soft cloth. The specimens thus cleaned shall be kept wrapped ina clean, dry cloth until tested. That part of the specimen to bei
47、mmersed in the test solution shall not be handled. Care shallbe taken to avoid 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
48、about 21C(70F), and adding sufficient 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
49、 of the concentratedsolution with distilled 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. The test solution used for testingsamples shall be considered exhausted if it fails to blacken apiece of clean copper as described above (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 m
