1、Designation: B246 05 (Reapproved 2010)Standard Specification forTinned Hard-Drawn and Medium-Hard-Drawn Copper Wirefor Electrical Purposes1This standard is issued under the fixed designation B246; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specif
3、ication covers tinned hard-drawn andmedium-hard-drawn round copper wire for electrical purposes.1.2 The SI values of resistance and density are to beregarded as standard. For all other properties, values stated ininch-pound units are to be regarded as the standard. The valuesgiven in parentheses are
4、 provided for information purposesonly.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 regulatory l
5、imitations prior to use. For hazard state-ment, see Sections 10 and 13.2. Referenced Documents2.1 The following documents of the issue in effect on thedate of material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:2B5 Specification for High Conductivity
6、 Tough-Pitch Cop-per Refinery ShapesB49 Specification for Copper Rod Drawing Stock for Elec-trical PurposesB170 Specification for Oxygen-Free Electrolytic CopperRefinery ShapesB193 Test Method for Resistivity of Electrical ConductorMaterials2.3 National Bureau of Standards:3NBS Handbook 100Copper Wi
7、re Tables3. Ordering Information3.1 Orders for material under this specification shall includethe following information:3.1.1 Quantity of each size,3.1.2 Wire size, diameter in inches (see 5.1 and Table 1),3.1.3 Type of copper, if special (see 4.2),3.1.4 Temper (see 7.1 and Table 1),3.1.5 Package si
8、ze (see 18.1),3.1.6 Special package marking, if required, and3.1.7 Place of inspection (Section 16).4. Materials and Manufacture4.1 The tinned wire shall be made by coating hard-drawnand medium-hard-drawn copper wire with commercially puretin (see Note 1). For purposes of this specification, the tin
9、 shallbe considered commercially pure if the total of other elements,exclusive of copper, does not exceed 1 %. Notwithstanding theprevious sentence, chemical analysis of the tin coating or of thetin used for coating shall not be required under this specifica-tion. Adequacy of the tin coating is ensu
10、red by the continuityof coating and adherence of coating requirements (Sections 9and 13, respectively).4.2 The copper shall be copper of such quality and puritythat the finished product shall have the properties and charac-teristics prescribed in this specification.NOTE 1Specifications B5, B49, and
11、B170 define the materials suit-able for use.4.3 Copper bars of special qualities, forms, or types, as maybe agreed upon between the manufacturer and the purchaser,and which will conform to the requirements prescribed in thisspecification may also be used.1This specification is under the jurisdiction
12、 of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.04 onConductors of Copper and Copper Alloys.Current edition approved Oct. 1, 2010. Published December 2010. Originallyapproved in 1951. Discontinued 1993 and reinstated 1994. Last previous editionappr
13、oved in 2005 as B246 05. DOI: 10.1520/B0246-05R10.2For referenced ASTM standards, visit the ASTM website, 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.3Available
14、from National Technical Information Service (NTIS), U.S. Depart-ment of Commerce, 5285 Port Royal Rd., Springfield, VA 22161.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Dimensions, Mass, and Permissible Variations5.1 The wire
15、sizes shall be expressed as the diameter of thecoated wire in decimal fractions of an inch to the nearest0.0001 in. (0.001 mm) (Explanatory Note 5).5.2 The coated wire shall not vary from the specifieddiameter by more than +3 % or 1 %.5.3 Ten percent, but not less than five coils or spools (or all,i
16、f the lot is less than five) from any lot of wire shall be takennear each end and one near the middle. If any of these selectedcoils or spools fails to conform to the requirements prescribedin 5.2, all coils or spools shall be gaged in the mannerspecified.6. Workmanship, Finish, and Appearance6.1 Th
17、e tin coating shall consist of a smooth continuouslayer, firmly adhering to the surface of the copper.6.2 The wire shall be free from all imperfections notconsistent with the best commercial practice.7. Tensile Properties7.1 The tinned wire shall conform to the requirements as totensile properties p
18、rescribed in Table 1 (Explanatory Note 1).7.2 For wire the nominal diameter of which is more than0.001 in. (1 mil) or 0.025 mm greater than a size listed in Table1, but which is less than that of the next larger size, therequirements of the next larger size shall apply.7.3 Tension tests shall be mad
19、e on representative samples.Determine the elongation of the wire as the permanent increasein length due to the breaking of the wire in tension, measuredbetween gage marks placed originally 10 in. (250 mm) apartupon the test specimen (Explanatory Note 2).7.4 If any part of the fracture takes place ou
20、tside the gagemarks or in the jaws of the testing machine, or if an examina-tion of the specimen indicates a flaw, the value obtained maynot be representative of the material. In such cases the test maybe discarded and a new test made.7.5 RetestsIf upon testing a specimen from any coil orspool of wi
21、re, the results do not conform to the requirementsprescribed in Table 1, two additional specimens shall be tested,and the average of the three tests shall determine the accep-tance or rejection of the coil or spool.8. Resistivity8.1 Electrical resistivity shall be determined on representa-tive speci
22、mens by resistance measurements made in accor-dance with Test Method B193. At a temperature of 20C theresistivity of coated wire shall not exceed the values prescribedin Table 2 (Explanatory Note 3).9. Continuity of Coating9.1 The continuity of coating on the wire shall be deter-mined on representat
23、ive samples taken before stranding orinsulating (Explanatory Note 4).9.2 The continuity of the tin coating shall be determined bythe sodium polysulfide test, which shall be applied as specifiedin Sections 10-12.10. Specimens for Coating Tests10.1 Length of SpecimensTest specimens shall each havea le
24、ngth of about 6 in. They shall be tagged or marked tocorrespond with the coil, spool, or reel from which they werecut.TABLE 1 Tensile RequirementsTinned Medium-Hard-Drawn WireTinned Hard-Drawn Wire Tensile Strength, min.Diameter Area at 20C Tensile Strenth, min.Elongationin 10 in.(250mm),%minpsi Mpa
25、Elongationin 10 in.(250mm),%minin. mm cmil in.2mm2psi Mpa min. max. min. max.0.2043 5.189 41738 0.03278 21.15 54100 370.6 1.7 42400 55300 290.4 378.8 1.90.1819 4.620 33088 0.02599 16.77 55100 377.4 1.6 43300 55700 296.6 381.5 1.70.1620 4.115 26244 0.02061 13.30 55900 382.9 1.4 44100 56000 302.1 383.
26、6 1.50.1443 3.665 20822 0.01635 10.55 56700 388.4 1.3 44900 56300 307.6 385.6 1.40.1285 3.264 16512 0.01297 8.367 57300 392.5 1.3 45500 56700 311.7 388.4 1.30.1144 2.906 13087 0.01028 6.632 57900 396.6 1.2 46000 57000 315.1 390.4 1.30.1019 2.588 10384 0.008155 5.262 58400 400.0 1.2 46500 57300 318.5
27、 392.5 1.20.0907 2.304 8226 0.006461 4.1684 58900 403.5 1.1 46900 57700 321.3 395.2 1.20.0808 2.052 6529 0.005128 3.308 59100 404.8 1.1 47200 58000 323.3 397.3 1.10.0720 1.829 5184 0.004072 2.627 59300 406.2 1.1 47300 58300 324.0 399.3 1.10.0641 1.628 4109 0.003227 2.082 59600 408.2 1.0 47600 58700
28、326.1 402.1 1.00.0571 1.450 3260 0.002561 1.652 59800 409.6 1.0 47800 59000 327.4 404.1 1.00.0508 1.290 2581 0.002027 1.308 59900 410.3 1.0 47900 59300 328.1 406.2 1.0TABLE 2 Electrical Resistivity RequirementsResistivity at 20CNominal Diameter lb/mile2g/m2in. mm Hard Medium-Hard Hard Medium-Hard0.2
29、043 to 0.103, incl 5.2 to 2.6, incl 943.92 938.85 0.1653 0.1644Under 0.103 to 0.0508, incl Under 2.6 to 1.3, incl 910.15 946.06 0.1594 0.1657B246 05 (2010)210.2 Treatment of SpecimensThe specimens shall be thor-oughly cleaned by immersion in a suitable solvent for theappropriate time required to rem
30、ove oil or grease from surface;then removed and wiped dry with a clean soft cloth(Cautionsee Explanatory Note 6). The specimens thuscleaned shall be kept wrapped in a clean, dry cloth until tested.That part of the specimen to be immersed in the test solutionshall not be handled. Care shall be taken
31、to avoid abrasion bythe cut ends.11. Special Solutions Required11.1 Hydrochloric Acid Solution (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. Aportion of HCl solution having a volume of 180 mL shall beconsidered to be e
32、xhausted when the number of test specimensprescribed in Table 3 of a size as indicated in Section 12 havebeen immersed in it for two cycles.11.2 Sodium Polysulfide Solution (sp gr 1.142)A concen-trated solution shall be made by dissolving sodium sulfide cpcrystals in distilled water until the soluti
33、on is saturated at about21C, and adding sufficient flowers of sulfur (in excess of 250g/L of solution) to provide complete saturation as evidenced 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 di
34、luting a portion of the concentratedsolution with distilled water to a specific gravity of 1.142 at15.6C. The sodium polysulfide test solution shall have suffi-cient strength to blacken thoroughly a piece of clean untinnedcopper wire in 5 s.Aportion of the test solution used for testingsamples shall
35、 not be considered to be exhausted until it fails toblacken a piece of clean copper as described here (ExplanatoryNote 6).12. Procedure for Coating Continuity Test12.1 Immersion of SpecimensImmerse a length of at least412 in. from each of the clean specimens, in accordance withthe following cycles,
36、in test solutions maintained at a tempera-ture between 15.6 and 21C:12.1.1 Immerse the specimen for 1 min in the HCl solutiondescribed in 11.1, wash, and wipe dry.12.1.2 Immerse the specimen for 30 s in the sodiumpolysulfide solution described in 11.2, wash, and wipe dry.12.1.3 Immerse the specimen
37、for 1 min in HCl solutiondescribed in 11.1, wash, and wipe dry.12.1.4 Immerse the specimen for 30 s in the sodiumpolysulfide solution described in 11.2, wash, and wipe dry.12.2 Washing SpecimensAfter each immersion, immedi-ately wash thoroughly the specimens in clean water and wipedry with a clean,
38、soft cloth.12.3 Examination of SpecimensAfter the operations de-scribed in 12.1 and 12.2, examine the specimens to ascertain ifcopper exposed through openings in the tin coating has beenblackened by action of the sodium polysulfide. The specimensshall be considered to have failed if by such blackeni
39、ngexposed copper is revealed. Pay no attention to blackeningwithin 0.5 in. of the cut end.13. Mechanical Test for Adhesion of Coating13.1 Length of SpecimensTest specimens shall be ap-proximately 12 in. in length and shall be tagged or marked tocorrespond with the coil, spool, or reel from which the
40、y are cut.13.2 Preparation of SpecimenThoroughly clean the speci-mens, if required, by immersion in a suitable solvent for theappropriate time required to remove oil and grease fromsurface, then remove and dry (CautionExplanatory Note 6).Store the specimens thus cleaned wrapped in a clean, dry cloth
41、until tested. Do not handle that part of the specimens to beimmersed in the test solution. Use care to avoid abrasion of thesurface to be subjected to test.13.3 Wrapping ProcedureSlowly wrap the test specimenin a suitable manner in an open helix around a polishedmandrel having rounded ends and a dia
42、meter equal to fourtimes the diameter of the specimens. Use care not to stretch thespecimen during the wrapping operation. Make the spacing ofthe consecutive turns approximately equal to the diameter ofthe wire. Do not use more than three turns for the test.13.4 Immersion Test Remove the helically w
43、rapped por-tion of the test specimen from the mandrel and completelyimmerse in the sodium polysulfide solution (see 11.2) for 30 sat the temperature in accordance with 12.1. On removal fromthe sodium polysulfide solution, rinse the specimen immedi-ately in clean water and remove the excess by shakin
44、g.13.5 Examination of SpecimenExamine visually the outerperipheral surface of the helically wrapped portion of thespecimen. Any cracking or parting of the coating in this areashown by blackening of the copper shall be cause for rejection.A grayish appearance of the coating after immersion shall notc
45、onstitute failure.13.6 RetestIn the event of failure, two additional speci-mens shall be tested. If either of these specimen fails, the coil,reel, or spool shall be rejected.14. Joints14.1 Joints shall not be made in the wire after it has beendrawn to size or coated. Joints in the wire or rods prior
46、 to finaldrawing shall be made in accordance with the best commercialpractice (Explanatory Note 8).TABLE 3 Limiting Number of Test Specimens for Coating TestsNominal DiameterMaximum Number ofSpecimens to Be Testedfor Two Cycles in 180 mLof Acid Solutionin. mm0.2043 to 0.141, incl 5.2 to 3.6, incl 2U
47、nder 0.141 to 0.0851, incl Under 3.6 to 2.2, incl 4Under 0.0851 to 0.0508, incl Under 2.2 to 1.3, incl 6B246 05 (2010)315. Density15.1 For the purpose of calculating mass per unit length,cross sections, etc., the density of the copper shall be taken as8.89 g/cm3or 0.32117 lb/in.3at 20C (Explanatory
48、Note 9).16. Inspection16.1 All tests and inspection shall be made at the place ofmanufacture unless otherwise especially agreed upon betweenthe manufacturer and the purchaser at the time of purchase. Themanufacturer shall afford the inspector representing the pur-chaser all reasonable facilities to
49、satisfy him that the materialis being furnished in accordance with this specification.17. Rejection17.1 Wire that shows exposed copper by blackening aftertesting in the sodium polysulfide solution in accordance withSections 11 and 12, or that fails to conform to the otherrequirements of this specification, shall be rejected.18. Packaging and Package Marking18.1 Package sizes shall be agreed upon between the manu-facturer and the purchaser in the placing of individual orders(Explanatory Note 10).18.2 The coated wire shall be protected against damage ino
