1、Designation: B986 13Standard 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 adopt
2、ion 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.1. S
3、cope1.1 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 test method is intended for conductors that are onetype of wire (non-composite). T
4、he 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 parentheses are mathematicalconversions to SI units that are provided for informat
5、ion 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-priate safety and health practices and determine the applica-bility of regulatory
6、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 Specification for 8000 Series Aluminum Alloy Wirefor Electrical PurposesAnnealed and Int
7、ermediate 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, referto Terminology B354.4. Significance and Use4.1 This test method is design
8、ed 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 Balance, for measurement of mass, accurate to 0.1 %.5.3 Steel Scale, for measurem
9、ent 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 tensile test in accordance with Test MethodsE8/E8M and with a rate of loading not to e
10、xceed 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 testspecimens shall be 2 ft (610 mm) minimum (Explanatory Note2).6.2.2 Measure the length
11、 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.NOTE 1Correction for temperature variation need not be made, sincethe error introduced in the length measurement
12、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):1This practice is under the jurisdiction of ASTM Committee B01 on ElectricalConductors and is the direct
13、responsibility of Subcommittee B01.02 on Methods ofTest and Sampling Procedure.Current edition approved April 1, 2013. Published April 2013. DOI: 10.1520/B098613.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
14、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 States1TS 5 BL CM! 3 MF 3 100 1 k! 100#where:TS = tensile strength of the stranded conductor
15、, lb/in.2(N/mm2),BL = breaking load measurement read directly from thetensile tester, lb (N),CM = mass of conductor per unit length, lb/0000 ft (kg/km),MF = material factor, lb/in2 1000 ft (kg/mm2 km), (Table1 and Explanatory Note 4 and Note 5), andk = increment (increase) in mass and electrical res
16、istance(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 TestMethods E8/E8M.9. Keywords9.1 breaking loads; mass methods; metallic conductors;te
17、nsile 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 be deformed. Theformula for tensile strength based on a mass method can be derived a
18、sfollows: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 generalized formula for stranded conductor cross-sectional area based on mass is:A= M/L 3 D! #
19、 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 stranded conductor, lb/in.2(N/mm2),BL = breaking load measurement read directly form the
20、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 7.1 is based on conductor mass in lbs/1000ft (kg/km).The material factor in 7.1 is
21、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 may exceed the extensometerloading capacity, the user of the standard may elect to
22、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 the failure is suspected to be an error in the testing procedure,set-up, or factors o
23、ther 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 for retesting the production unit.NOTE 4The calculations and method can be applied
24、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 of a coated conductor is not constant, buta var
25、iable 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 considered the same as copper.Refer to Eq 4 an
26、d Eq 5 from Explanatory Note 1 for material factorcalculation using the calculated effective density.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 %
27、) 0.32179 (8.91) 3861 (8.91)Copper-Silver coated Class B (2.50 %) 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 Stee
28、l (CCS30) 0.29440 (8.15) 3533 (8.15)Copper-Clad Steel (CCS40) 0.29750 (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) 0.09800
29、0 (2.71) 1176 (2.71)ASee Explanatory Note 4 and Note 5.B986 132Effective Density=1/ coating%/100! coating density! 112 coating % 100! base metal density! #where:Density = coating or base metal density, lb/in.3(g/cm3). Note that 1.0g/cm3= 1.0 kg/mm3when referring to Eq 5 from Explana-tory Note 1 to d
30、etermine 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 expressly advised that determination of the validity of any such patent rights, and the ris
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