1、Designation: B267 07 (Reapproved 2013)Standard Specification forWire for Use In Wire-Wound Resistors1This standard is issued under the fixed designation B267; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. 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 round wire and ribbon withcontrolled electrical properties for use in wire-wound resis-tance units and s
3、imilar applications, but not for use as electricalheating elements.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.1.3 This standard
4、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 become familiarwith all hazards including those identified in the appropriateMaterial Safety Data Sheet (MSDS) for this product/materialas provided by the m
5、anufacturer, to establish appropriatesafety and health practices, and determine the applicability ofregulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B63 Test Method for Resistivity of Metallically ConductingResistance and Contact MaterialsB77 Test Method for Thermoelect
6、ric Power of Electrical-Resistance AlloysB84 Test Method for Temperature-Resistance Constants ofAlloy Wires for Precision Resistors3. Significance and Use3.1 This specification on wire and ribbon contains thegeneric chemistry and requirements for resistivity, temperaturecoefficient of resistance, th
7、ermal emf versus copper resistancetolerances, and mechanical properties of bare wire, as well asthe wire enamels and insulations of alloys normally used in themanufacture of wound resistors.4. Alloy Classes4.1 Fifteen classes of alloys are covered by this specificationas listed in Table 1.5. Elongat
8、ion5.1 The wire shall conform to the requirements for elonga-tion as prescribed in Table 1, when tested on a 10-in. (254-mm)length.6. Resistivity6.1 The bare wire shall conform to the requirements fornominal resistivity as prescribed in Table 1.6.2 Actual resistivity shall not vary from nominal resi
9、stivityby more than 65 % for Alloy Classes 1 to 4 inclusive, and610 % for Alloy Classes 5 to 11 inclusive.7. Nominal Electrical Resistance per Unit Length7.1 The nominal resistance per unit length for round wireshall be calculated from the nominal resistivity and the nominalcross-sectional area.NOTE
10、 1When ribbon or flat wire is produced by rolling from roundwire, the cross section departs from that of a true rectangle by an amountdepending on the width-to-thickness ratio and the specific manufacturingpractice. The conventional formula for computing ohms per foot and feetper pound is to conside
11、r the cross section as 17 % less than a true rectanglewhen width is more than 15 times the thickness and 6 % less than a truerectangle in other cases. This is not valid in view of modern rollingequipment and practices, but still is widely used as a basis of description.Ribbon actually is made to a s
12、pecified resistance per foot, and no toleranceis specified for thickness.An alternative and a closer approximation wouldbe that for ribbon rolled round wire, the electrical resistance would becalculated on a cross 6 % less than a true rectangle.8. Temperature Coefficient of Resistance8.1 The change
13、in resistance with change in temperature,expressed as the mean temperature coefficient of resistancebased on the reference temperature of 25C, shall be within thelimits specified in Table 1, Columns 4 and 6, over thecorresponding temperature ranges specified in Columns 5 and7. The mean temperature c
14、oefficient of resistance referred to25C is defined as the slope of a chord of an arc. This slope isdetermined from the following equation:m5 R/R25T! 31061This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of Subcommittee
15、B02.10 on Thermostat Metals and Electrical Resistance Heating Materials.Current edition approved May 1, 2013. Published May 2013. Originallyapproved in 1952. Last previous edition approved in 2007 as B267 07. DOI:10.1520/B0267-07R13.2For referenced ASTM standards, visit the ASTM website, www.astm.or
16、g, 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 States1where:m= mean
17、temperature coefficient of resistance, ppm/C,Table 1, Columns 4 and 6, R = change in resistance over temperature range indicatedin Table 1, Columns 5 and 7,R25= resistance at 25C,T = temperature range indicated in Table 1, Columns 5and 7.8.2 ForAlloy Classes 1, 2, and 5, the temperature coefficienta
18、s specified in Table 1 of any 10-ft (3-m) length shall not varymore than 3 ppm/C from that of any other 10-ft length on thesame spool or coil.9. Thermal EMF with Respect to Copper9.1 The thermal electromotive force (emf) with respect tocopper shall fall within the limits shown in Table 1, in thecorr
19、esponding temperature ranges.10. Permissible Variations in Electrical Resistance10.1 The actual resistance per unit length of any wirefurnished under these specifications shall not vary from thenominal resistance by more than the following amounts:Form PermissibleVariation, %Over 0.005 in. (0.127 mm
20、) in diameter 50.002 to 0.005 in. (0.051 to 0.127 mm) in diameter, incl 8Under 0.002 in (0.051 mm) in diameter 10Ribbon 510.2 ForAlloy Classes 1 to 4 inclusive, the actual resistanceof any 1-ft length of wire in one spool or coil shall not vary bymore than 3 % from the actual resistance of any other
21、 1 ft ofwire in the same spool or coil.10.3 For Alloy Classes 5 to 11 inclusive, the actual resis-tance of any 1-ft length of wire in one spool or coil shall notvary by more than 5 % from the actual resistance of any other1 ft of wire in the same spool or coil.11. Permissible Variations in Dimension
22、s11.1 Permissible variations in dimensions of bare wire arenot specified, since these materials are used for resistancepurposes, in which the resistivity and the electrical resistanceper unit length, rather than the dimensions, are of primeimportance. The electrical resistance per unit length can be
23、determined more accurately than the dimensions of very smallwire.TABLE 1 Classes of Alloys and RequirementsAlloyClassAAlloy Composition,approximate, %Resistivity,cmil/ft(m)Mean Temperature Coefficient of Resistance, mppm forC Over Temperature Range, TMaximum Thermal emfversus Copper, mV/CBElongation
24、 in 10 in., min, %T mT mV/CTemperatureRange, TCOver0.002in.DinDiameter0.002 to0.001in.DinDiameter0.0009in.DinDiameterand Finer12 3 456789101121a nickel base, nonmagnetic 800 (1.330) 0, 20 +25 to 55 0, 20 +25 to +105 +0.003 65 to +250 10 5 31b nickel base, nonmagnetic 800 (1.330) 0, 10 +25 to 55 0, 1
25、0 +25 to +105 +0.003 65 to +150 10 5 31c nickel base, nonmagnetic 800 (1.330) 0, 5 +25 to 55 0, 5 +25 to +105 +0.003 65 to +150 10 5 32a iron base, magnetic 800 (1.330) 0, 20 +25 to 55 0, 20 +25 to +105 0.004 65 to +200 10 5 32b iron base, magnetic 800 (1.330) 0, 10 +25 to 55 0, 10 +25 to +105 0.004
26、 65 to +150 10 5 33a 80 nickel, 20 chromium 650 (1.081) +80, 20 +25 to 55 +80, 20 +25 to +105 +0.006 65 to +250 15 5 33b 80 nickel, 20 chromium,stabilized675 (1.122) +60, 20 +25 to 55 +60, 20 +25 to +105 +0.006 65 to +250 15 5 34 60 nickel, 16 chromium,balance iron675 (1.122) +140, 30 +25 to 55 +140
27、, 30 +25 to +105 +0.002 65 to +200 15 5 35a 55 copper, 45 nickel 300 (0.499) 0, 20 +25 to 55 0, 20 +25 to +105 0.045 65 to + 150 15 5 35b 55 copper, 45 nickel 300 (0.499) 0, 40 +25 to 55 0, 40 +25 to +105 0.045 65 to +150 15 5 36 manganin type 290 (0.482) 0, 15EE0, 15EE0.003 +15 to +35 15 5 37 77 co
28、pper, 23 nickel 180 (0.299) +180, 30 +25 to 55 +180, 30 +25 to +105 0.037 65 to +150 15 5 38 70 nickel, 30 iron 125 (0.199) +3600, 400 +25 to 50 +4300, 400 +25 to +104 0.040 50 to +100 15 5 39 90 copper, 10 nickel 90 (0.150) +450, 50 +25 to 55 +450, 50 +25 to +105 0.026 65 to +150 15 5 310 94 copper
29、, 6 nickel 60 (0.100) +700, 200 +25 to 55 +700, 200 +25 to +105 0.022 65 to +150 15 5 311 98 copper, 2 nickel 30 (0.050) +1400, 300 +25 to 55 +1400, 300 +25 to +105 0.014 65 to +150 15 5 3AAlloy Classes 1a to 8 inclusive are designed to provide controlled temperature coefficients. Values shown for o
30、ther classes are for information only. All values are basedon a reference temperature of 25C.BAlloy Classes 1a, 1b, 1c, 2a, 2b, 3a, 4, and 6 are designed to give a low emf versus copper. Values shown for other classes are for information only. Maximum indicatesthe maximum deviation from zero and the
31、 plus or minus sign the polarity of the couple.CThe maximum temperature values listed apply to the alloy wire only. Caution should be exercised pending knowledge of the maximum temperature of use for the coatingmaterial involved.DIf metric sizes are desired, 1 in. = 25.4 mm.EAlloy Class 6 (manganin
32、type for resistors), has a temperature-resistance curve of parabolic shape with the maximum resistance normally located between 25 and 30C.Thus, Columns 5 and 7 cannot indicate 25C as a limit but mmay be expressed as a maximum of + 15 ppm for 15C to the temperature of maximum resistance and amaximum
33、 of 15 ppm from the temperature of maximum resistance to 35C. All of the information included in this note is based on measurements made in accordancewith Test Method B84.B267 07 (2013)212. Finish12.1 The wire shall be as uniform and free from kinks, curls,and surface defects such as seams, laminati
34、ons, scale, and otherirregularities as the best commercial practice will permit.13. Enamel Coatings13.1 Enamel coatings shall include any baked-on film ofinsulating material, such as varnish enamel, polyurethane,vinyl acetal, etc. and shall conform to the requirementsprescribed in 13.2 to 13.7.13.2
35、The physical dimensions of the enamel film shallconform to the requirements specified in Table 2.13.3 The continuity of dielectric strength of medium orheavy enamel shall show a maximum of 10 breaks/100 ft. Thetest circuit shall have a recording sensitivity of 300 000 620 % with 150 V across the coa
36、ting. The tension on the wireshall not exceed one half of its yield strength.13.4 The coating shall have excellent adherence to the wireon which it is applied, allowing elongation until the wirebreaks without rupture of the coating or loosening of its bond.The surface of the coating shall be smooth
37、and uniform. Theenamel shall not be underbaked so that one turn adheres to thenext on a spool.13.5 The recommended maximum temperature of use ofwire coated with various materials shall be approximately aslisted in Table 3.13.6 The nominal temperatures specified in 13.5 do notrestrict the use of mate
38、rials at other temperatures whencombined with insulation systems and proven by system testprocedures.13.7 Enameled wire shall withstand the following solubilitytest: Immerse a sample of the enameled wire in neutral mineraltransformer oil for 48 h at 100C, after which the enamel shallnot be sufficien
39、tly softened so that it can be rubbed off withcheese cloth. The rubbing action shall be sufficiently slow sothat the coating is not heated by friction. The test shall be made2 to 10 min after removal of the wire from the oil, lightlywiping off the excess oil.14. Insulated Coverings14.1 Insulated cov
40、erings on wire shall include any wrappedtextile covering such as cotton, silk, nylon, glass, etc. It shallTABLE 2 Dimensions of Enamel Coated WireANominal Bare Wire Size Light Coated Wire Medium Coated Wire Heavy Coated WireB resistivity; resistor alloys; resistors;wire woundASTM International takes
41、 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 riskof infringement of such rights, are entirely their own resp
42、onsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addresse
43、d to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. 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
44、address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).B267 07 (2013)5
