1、Designation: B973 10Standard Specification forTin-Coated Braid and Ribbon Flat Copper Wire intended foruse in Electronic Application1This standard is issued under the fixed designation B973; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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.1. Scope1.1 This specification covers tin-coated hard-drawn copperbraid and ribbon flat wire intended for elec
3、tronic application(Explanatory Note 1).1.2 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 information onlyand are not considered standard.1.2.1 ExceptionsThe SI values for density, res
4、istivity, andvolume are to be regarded as standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of
5、regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B1 Specification for Hard-Drawn Copper WireB3 Specification for Soft or Annealed Copper WireB49 Specification for Copper Rod Drawing Stock for Elec-trical PurposesB193 Test Method for Resistivity of Electrical ConductorMa
6、terialsB258 Specification for Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Usedas Electrical Conductors2.2 Other Standards:3NBS Handbook 100 Copper Wire Tables3. Ordering Information3.1 Orders for material under this specification shall includethe following informati
7、on:3.1.1 Quantity of each size,3.1.2 Wire size-thickness and width in inches (see 5.3),3.1.3 Type of copper, if special (see 4.2),3.1.4 Package size (see 10.1),3.1.5 Special packaging marking, if required, and3.1.6 Place of inspection (see 7.1).4. Material4.1 Tin for CoatingThe tin shall be electrop
8、lated for thecoating and shall be commercially pure (Explanatory Note 1).For purposes of this specification, the tin shall be consideredcommercially pure if the total of other elements, exclusive ofcopper, does not exceed 1%. Not withstanding the previoussentence, chemical analysis of the tin coatin
9、g or of the tin usedfor coating shall not be required under this specification.4.2 Copper-Base MetalThe base metal shall be copper ofsuch quality and purity that the finished product shall haveproperties and characteristics prescribed in this specification.NOTE 1Specifications B1, B3,orB49 defines c
10、opper suitable for use.5. General Requirements (See Section 8)5.1 Tensile and ElongationThe tin-coated copper flat wirein the hard drawn condition shall conform to elongationrequirements of 1% minimum to 5% maximum. The tensilestrength shall be 55 000 psi (379 MPa) minimum.5.2 Resistivity (Explanato
11、ry Note 3)The electrical resis-tivity of the coated wire at a temperature of 20C shall notexceed the values prescribed in Table 1.5.3 Dimensions and Permissible VariationsThe flat wiresizes shall be expressed as the thickness and width of the wirein decimal fractions of an inch to the nearest 0.0001
12、 in. (0.0025mm). The tin-coated flat wire shall not vary from the specifiedthickness and width by more than the amounts specified inTable 2 and Table 3, respectively.5.4 Continuity of CoatingThe tin coating shall be con-tinuous. The continuity of coating on the flat wire shall bedetermined on repres
13、entative samples taken before braidingapplications or insulating. The continuity of coating shall bedetermined by the hydrochloric acid-sodium polysulfide test inaccordance with 6.4.1This test method is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibi
14、lity of Subcommittee B01.04 onConductors of Copper and Copper Alloys.Current edition approved April 1, 2010. Published May 2010.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informatio
15、n, refer to the standards Document Summary page onthe ASTM website.3Available from National Technical Information Service (NTIS), 5285 PortRoyal Rd., Springfield, VA 22161, http:/www.ntis.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
16、States.5.5 JointsNecessary joints in the wire and rods prior tofinal coating and drawing shall be made in accordance with thebest commercial practice. There shall be no uncoated joints inthe final product.5.6 FinishThe coating shall consist of a smooth continu-ous layer, firmly adherent to the surfa
17、ce of the copper. The wireshall be free of all imperfections not consistent with the bestcommercial practice.6. Test Methods6.1 Tensile Strength and Elongation (Explanatory Note 4):6.1.1 The tensile strength, expressed in pounds per squareinch, shall be obtained by dividing the maximum load carriedb
18、y the specimen during the tension test by the originalcross-sectional area of the specimen. Tensile strength andelongation may be determined simultaneously on the samespecimen.6.1.2 The elongation of the flat wire may be determined bymeasurements made between the jaws of the tensile testingmachine.
19、The zero length shall be the distance between thejaws at the start of the tension test and be as near 10 in. (254mm) as practicable. The final length shall be the distancebetween the jaws at the time of rupture. The fracture shall bebetween the jaws of the testing machine and not closer than 1in. (2
20、5.4 mm) to the jaw.6.2 Resistivity (Explanatory Note 3)The electrical resis-tivity of the material shall be determined in accordance withTest Method B193. The purchaser may accept certification thatthe wire was drawn from rod stock meeting the internationalstandard for annealed copper instead of res
21、istivity tests on thefinished wire.6.3 Dimensional MeasurementsDimensional measure-ments for width and thickness shall be made with a micrometercaliper equipped with a vernier graduated in 0.0001 in. (0.0025mm). Measurements shall be made on at least three places oneach unit selected for this test.
22、Any measurement takenexceeding the dimensions and permissible variation require-ments in 5.4 shall constitute failure to meet the dimensionalconformance criterion.6.4 Continuity of Coating:6.4.1 Specimens:6.4.1.1 Length of SpecimensTest specimens shall have alength of about 6 in. (152 mm). They shal
23、l be tagged or markedto correspond with the coil, spool, or reel from which they werecut.6.4.1.2 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 ( Caution-see Explanatory N
24、ote 5). The specimensthus cleaned shall be kept wrapped in a clean, dry cloth untiltested. That part of the specimen to be immersed in the testsolution shall not be handled. Care shall be taken to avoidabrasion by the cut ends.6.4.2 Special Solutions Required:6.4.2.1 Hydrochloric Acid Solution (HCl)
25、 (sp gr 1.088)Commercial HCl (sp gr 1.12) shall be diluted with distilledwater to a specific gravity of 1.088 measured at 15.6C (60F).A portion of HCl solution having a volume of 180 mL shall beconsidered to be exhausted when the number of test specimensprescribed in Table 4 of a size as indicated i
26、n 6.4.3 have beenimmersed in it for two cycles.6.4.2.2 Sodium Polysulfide Solution (sp gr 1.142) (Explana-tory Note 6)A concentrated solution shall be made bydissolving sodium sulfide crystals (cp) in distilled water untilthe solution is saturated at about 21C (70F), and addingsufficient flowers of
27、sulfur (in excess of 250 g/L of solution) toprovide complete saturation, as shown by the presence in thesolution of an excess of sulfur after the solution has beenallowed to stand for at least 24 h. The test solution shall bemade by diluting a portion of the concentrated solution withdistilled water
28、 to a specific gravity of 1.135 to 1.145 at 15.6C(60F). The sodium polysulfide test solution should havesufficient strength to blacken thoroughly a piece of cleanuntinned copper wire in 5 s. The test solution used for testingTABLE 1 Electrical Resistivity RequirementsThickness Range,Inch (mm)Resisti
29、vity at 20CVlb/mile20.0008 to 0.0012 (0.020 to 0.031), incl 1006.00.0013 to 0.0016 (0.033 to 0.041), incl 972.450.0017 to 0.0024 (0.043 to 0.061), incl 961.760.0025 to 0.0048 (0.064 to 0.122), incl 951.310.0049 to 0.0100 (0.125 to 0.254), incl 941.08TABLE 2 Permissible Variations in ThicknessNominal
30、 Thickness Range,Inch (mm)Tolerance,Inch (mm)0.0010 to 0.0014 (0.025 to 0.036) +/- 0.0002 (0.005)0.0015 to 0.0019 (0.038 to 0.048) +/- 0.0003 (0.008)0.0020 to 0.0049 (0.051 to 0.124) +/- 0.0004 (0.010)0.0050 to 0.0100 (0.127 to 0.254) +/- 0.0005 (0.013)TABLE 3 Permissible Variations in WidthNominal
31、Width Range,Inch (mm)Tolerance,Inch (mm)0.0100 to 0.0499 (0.254 to 1.27) +/- 0.0013 (0.033)0.0500 to 0.0699 (1.27 to 1.78) +/- 0.0015 (0.038)0.0700 to 0.0999 (1.78 to 2.54) +/- 0.0020 (0.051)0.1000 to 0.1249 (2.54 to 3.17) +/- 0.0030 (0.076)0.1250 to 0.1500 (3.18 to 3.81) +/- 0.0040 (0.102)TABLE 4 L
32、imiting Number of Test Specimens for Coating TestAEquivalent RoundNominal DiameterMaximum Number of Specimensto be Tested for 2 Cyclesin 180 mL of Acid Solutionin. mmUnder 0.0851 to 0.0501,inclUnder 2.2 to 1.3,incl6Under 0.0501 to 0.0381,inclUnder 1.3 to 0.97,incl10Under 0.0381 to 0.0301,inclUnder 0
33、.97 to 0.76,incl12Under 0.0301 to 0.0030,inclUnder 0.76 to 0.076,incl14ASee Explanatory Note 2 for equivalent round calculation.B973 102samples shall be considered exhausted if it fails to blacken apiece of clean copper as described above.6.4.3 Procedure:6.4.3.1 Immersion of SpecimensImmerse a lengt
34、h of atleast 4.5 in. (114 mm) from each of the clean specimens, inaccordance with the following cycles, in test solutions main-tained at a temperature between 15.6 and 21C (60 and 70F):(1) Immerse the specimen for 1 min in the HCl solutiondescribed in 6.4.2, wash, and wipe dry; (2) immerse thespecim
35、en for 30 s in the sodium polysulfide solution describedin 6.4.2, wash, and wipe dry; (3) immerse the specimen for 1min in the HCl solution, wash, and dry; (4) immerse thespecimen for 30 s in the sodium polysulfide solution, wash, andwipe dry.6.4.3.2 Washing Specimens After each immersion, imme-diat
36、ely wash the specimens thoroughly in clean water and wipedry with a clean, soft cloth.6.4.3.3 Examination of SpecimensAfter immersion andwashing, examine the specimens to ascertain if copper exposedthrough openings in the tin coating has been blackened byaction of the sodium polysulfide. The specime
37、ns shall beconsidered to have failed if, by such blackening, exposedcopper is revealed. No attention shall be paid to blackeningwithin 0.5 in. (12.7 mm) of the cut end. A grayish brownappearance of the coating shall not constitute failure.6.5 FinishSurface-finish inspection shall be made withthe una
38、ided eye (normal spectacles excepted).7. Inspection7.1 General (Explanatory Note 7)Unless otherwise speci-fied in the contract or purchaser order, the manufacturer shallbe responsible for the performance of all inspection and testrequirements specified.7.1.1 All inspections and tests shall be made a
39、t the place ofmanufacture unless otherwise especially agreed upon betweenthe manufacturer and the purchaser at the time of purchase.7.1.2 The manufacturer shall afford the inspector represent-ing the purchaser all reasonable manufacturers facilities tosatisfy him that the material is being furnished
40、 in accordancewith this specification.7.1.3 Unless otherwise agreed upon between the purchaserand the manufacturer, conformance of the wire to the variousrequirements listed in Section 5 shall be determined on samplestaken from each lot of wire presented for acceptance.7.1.4 The manufacturer shall,
41、if requested prior to inspec-tion, certify that all wire in the lot was made under suchconditions that the product as a whole conforms to therequirements of this specification as determined by regularlymade and recorded tests.7.2 Definitions Applicable to Inspection:7.2.1 lotany amount of wire of on
42、e type and size pre-sented for acceptance at one time.7.2.2 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.7.2.3 specimena length of wire removed for test pu
43、rposesfrom any individual production unit of the sample.7.3 Sample Size (Explanatory Note 7)The number ofproduction units in a sample shall be as follows:7.3.1 A full (100 % inspection) will be completed at everyset-up prior to running the order.7.3.2 For elongation, resistivity, dimensional measure
44、ments,and continuity of coating determinations, the sample shallconsist of sequential production units from the lot.7.3.3 For surface-finish inspection and for packaging in-spection (when specified by the purchaser at the time of placingthe order) the sample shall consist of sequential productionuni
45、ts from the lot.8. Conformance Criteria (Explanatory Note 7)8.1 Any lot of wire, the samples of which comply with theconformance criteria of Section 5, shall be considered ascomplying with the requirements of this standard. Individualproduction units that fail to meet one or more of the require-ment
46、s shall be rejected. If a failure of an individual productionunit occurs, material which was made between the non-conforming unit and the last production unit which passed theconformance criteria must be inspected for the non-conformingcharacteristic.9. Density (Explanatory Note 8)9.1 For the purpos
47、e of calculating linear densities, crosssections, etc., the density of the copper shall be taken as 8.89g/cm3(0.32117 lb/in.3) at 20C.10. Packaging and Shipping10.1 Package sizes shall be agreed upon by the manufac-turer and the purchaser in the placing of individual orders.10.2 The flat wire shall
48、be protected against damage inordinary handling and shipping.11. Keywords11.1 copper flat wire tin-coated; tin-coated annealed copperflat wire; tin-coated copper electrical equipment flat wire;tin-coated copper flat wireB973 103EXPLANATORY NOTESNOTE 1(1) It has been found that the tin coating on cop
49、per wireconsists of two parts, an envelope of pure tin on the outside, with anintermediate layer of copper-tin alloy. This tin alloy, as well as the amountof tin present, has an effect on the resistivity of the wire. Since the relativeamount of tin coating and alloy is greater as the size decreases, theresistivity of the wire increases as the size decreases.(2) The manufacturer and user of the standard should also giveconsideration to any agreed upon cast and camber requirements for ribbonwire applications.NOTE 2The equivalent round diameter
