1、Designation: B986 131Standard Test Method forDetermination of Tensile Strength by Mass Method forStranded Conductors Intended for use in ElectronicApplication1This standard is issued under the fixed designation B986; the number immediately following the designation indicates the year oforiginal adop
2、tion or, in the case 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.1NO
3、TEThe units for CM in Section 7.1 were editorially corrected in August 2013.1. Scope1.1 This test method covers the procedure for determiningthe tensile strength by a mass method for uninsulated strandedelectrical conductors intended for use in electronic application(Explanatory Note 1).1.1.1 The te
4、st method is intended for conductors that are onetype of wire (non-composite). The wire type being plain, clad,or coated and stranded together to operate mechanically andelectrically as a single conductor.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in pa
5、rentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered 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-pr
6、iate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Some specifichazards statements are given in Section 7 on Hazards.2. Referenced Documents2.1 ASTM Standards:2B354 Terminology Relating to Uninsulated Metallic Electri-cal ConductorsB800 Specific
7、ation for 8000 Series Aluminum Alloy Wirefor Electrical PurposesAnnealed and Intermediate Tem-persE4 Practices for Force Verification of Testing MachinesE8/E8M Test Methods for Tension Testing of Metallic Ma-terials3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method
8、, referto Terminology B354.4. Significance and Use4.1 This test method is designed as an inspection or accep-tance test of tensile strength for stranded metallic conductors.5. Apparatus5.1 Tensile Testing MachineMachines used for tensiontesting shall conform to the requirements of Practices E4.5.2 B
9、alance, for measurement of mass, accurate to 0.1 %.5.3 Steel Scale, for measurement of length, with smallerdivisions, not greater than132 in. (1 mm).5.4 Jig, or equivalent equipment, for cutting the conductorto length and at right angles to its axis.6. Procedure6.1 Breaking Load:6.1.1 Conduct tensil
10、e test in accordance with Test MethodsE8/E8M and with a rate of loading not to exceed 10 in./min(250 mm/min.) (Explanatory Note 2 and Note 3).6.2 Specimen Mass/Unit Length:6.2.1 Cut the test specimens, making sure that the ends areat right angles to the axis of the conductor. The length of testspeci
11、mens shall be 2 ft (610 mm) minimum (Explanatory Note2).6.2.2 Measure the length of the specimen at room tempera-ture (see Note 1) to the nearest132 in. (1 mm) and measure themass to within 60.1 % accuracy, converting to lb/1000 ft orkg/km, if weighed in other units.1This practice is under the juris
12、diction of ASTM Committee B01 on ElectricalConductors and is the direct responsibility of Subcommittee B01.02 on Methods ofTest and Sampling Procedure.Current edition approved April 1, 2013. Published April 2013. DOI: 10.1520/B0986-13E01.2For referenced ASTM standards, visit the ASTM website, www.as
13、tm.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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NOTE 1Cor
14、rection for temperature variation need not be made, sincethe error introduced in the length measurement by the temperaturevariation is less than the required accuracy of the length measurement.7. Calculation7.1 Calculate the tensile strength of the stranded conductoras follows (Explanatory Note 1):T
15、S 5 BL CM! 3 MF 3 100 1 k! 100#where:TS = tensile strength of the stranded conductor, lb/in.2(N/mm2),BL = breaking load measurement read directly from thetensile tester, lb (N),CM = mass of conductor per unit length, lb/1000 ft (kg/km),MF = material factor, lb/in2 1000 ft (kg/mm2 km), (Table1 and Ex
16、planatory Note 4 and Note 5), andk = increment (increase) in mass and electrical resistance(from product specification), %. If no k value is given,the use k =0.8. Precision and Bias8.1 Precision and BiasThe precision and bias of this testmethod for tensile strength are essentially as specified in Te
17、stMethods E8/E8M.9. Keywords9.1 breaking loads; mass methods; metallic conductors;tensile strengthEXPLANATORY NOTESNOTE 1Cross-sectional area of a stranded conductor used in elec-tronic applications can be difficult to determine since single wire diam-eters measured from the completed conductor can
18、be deformed. Theformula for tensile strength based on a mass method can be derived asfollows:The basic equation for tensile strength is:TS 5 BL A, where breaking load is adirect test measurement (1)The cross-sectional area can be derived based on density and mass perunit length. Thus, the generalize
19、d formula for stranded conductor cross-sectional area based on mass is:A= M/L 3 D! # 3 100 100 1 k! # (2)The generalized formula for tensile strength of the stranded conductorbased on a mass method can be derived as follows:TS 5 BL/M# 3 L 3 D 3 1001k! 100# (3)where:TS = tensile strength of the stran
20、ded conductor, lb/in.2(N/mm2),BL = breaking load measurement read directly form the tensile tester,lb (N),A = cross-sectional area, in.2(mm2),M = mass, lb (kg),L = length, in. (mm),D = density, lb/in.3(kg/mm3), andk = increment (increase) in mass and electrical resistance, %.The condensed formula in
21、 7.1 is based on conductor mass in lbs/1000ft (kg/km).The material factor in 7.1 is the densitylb/in.3!3 12 000 in./1000 ft!, or (4)The material factor in 7.1 is the densitykgmm3!3 1 3 106mmkm! (5)NOTE 2For rope constructions, where the sample may exceed thecapacity of the scale or the breaking load
22、 may exceed the extensometerloading capacity, the user of the standard may elect to break the sampledown into smaller constructions (that is, members of a rope) and averagethe results depending on the number of members tested.NOTE 3Should a failure occur, the manufacturer may retest if thecause of t
23、he failure is suspected to be an error in the testing procedure,set-up, or factors other than non-conformance with the tensile require-ments. For example, if a tensile test fails due to a break within the grippingregion, the failure may be due to a gripping deficiency, and that would bea valid cause
24、 for retesting the production unit.TABLE 1 Material Factory, MFAMetalDensity, lb/in.3(g/cm3)Material Factor, MF,lb/in.2 1000 ft(kg/mm2 km)Copper-Bare, Nickel coated copper 0.32117 (8.89) 3854 (8.89)Copper-Silver coated Class A (1.25 %) 0.32179 (8.91) 3861 (8.91)Copper-Silver coated Class B (2.50 %)
25、0.32241 (8.93) 3869 (8.93)Copper-Silver coated Class C (4.00 %) 0.32315 (8.95) 3787 (8.95)Copper-Silver coated Class D (6.10 %) 0.32420 (8.97) 3890 (8.97)Copper-Silver coated Class E (10.0 %) 0.32617 (9.03) 3914 (9.03)Copper-Clad Steel (CCS30) 0.29440 (8.15) 3533 (8.15)Copper-Clad Steel (CCS40) 0.29
26、750 (8.24) 3570 (8.24)Aluminum 1350 0.09750 (2.70) 1170 (2.70)Copper-Clad Aluminum (10A and 10H) 0.12000 (3.32) 1440 (3.32)Copper-Clad Aluminum (15A and 15H) 0.13118 (3.63) 1574 (3.63)Aluminum Alloy Series 8000 (per ASTM B800) 0.098000 (2.71) 1176 (2.71)ASee Explanatory Note 4 and Note 5.B986 1312NO
27、TE 4The calculations and method can be applied to metals,copper-alloys, or proprietary copper-alloys not covered in Table 1 bycalculating the appropriate material factor based on metal density. Refer toEq 4 and Eq 5 from Explanatory Note 1 for material factor calculation.NOTE 5The effective density
28、of a coated conductor is not constant, buta variable function of coating %. For the purposes of this standard, silvercoating density is taken as 0.37933 lb/in.3(10.5 g/cm3) and tin coatingdensity is taken as 0.2640 lb/in.3(7.31 g/cm3). For the purposes of thisstandard, the density of nickel shall be
29、 considered the same as copper.Refer to Eq 4 and Eq 5 from Explanatory Note 1 for material factorcalculation using the calculated effective density.Effective Density=1/ coating%/100! coating density! 112 coating % 100! base metal density! #where:Density = coating or base metal density, lb/in.3(g/cm3
30、). Note that 1.0g/cm3= 1.0 kg/mm3when referring to Eq 5 from Explana-tory Note 1 to determine the metric material factor.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expres
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33、tend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States.
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