1、Designation: B 267 07Standard Specification forWire for Use In Wire-Wound Resistors1This standard is issued under the fixed designation B 267; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in p
2、arentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 similar applicat
3、ions, 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 does not purpor
4、t 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 manufacturer, to
5、 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 Conduct-ing Resistance and Contact MaterialsB77 Test Method for Thermoelectric Power of
6、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, thermal emf ver
7、sus 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. Elongation5.1 The wi
8、re 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 resistivityby mor
9、e 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 1When ribbon
10、 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 consider the cross s
11、ection 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 specified resi
12、stance 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 in resistance
13、 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 coefficient of
14、 resistance referred to1This specification is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.10 on Thermostat Metals and Electrical Resistance Heating Materials.Current edition approved May 1, 2007. Published June 2007.
15、 Originallyapproved in 1952. Last previous edition approved in 2001 as B 267 90 (2001).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 Summar
16、y page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.25C is defined as the slope of a chord of an arc. This slope isdetermined from the following equation:am5 DR/R25DT! 3 106where:am= mean temperature coefficient
17、 of resistance, ppm/C, Table 1, Columns 4 and 6,DR = change in resistance over temperature range indi-cated in Table 1, Columns 5 and 7,R25= resistance at 25C,DT = temperature range indicated in Table 1, Columns 5and 7.8.2 ForAlloy Classes 1, 2, and 5, the temperature coefficientas specified in Tabl
18、e 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,inthecorresponding temperature
19、 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, 6%Over 0.005 in. (0.127 mm) in diameter 50.002
20、 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 1 ft ofwire in the
21、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 Dimensions11.1 Permissible va
22、riations 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 bedetermined more accu
23、rately than the dimensions of very smallwire.12. Finish12.1 The wire shall be as uniform and free from kinks, curls,and surface defects such as seams, laminations, scale, and otherirregularities as the best commercial practice will permit.TABLE 1 Classes of Alloys and RequirementsAlloyClassAAlloy Co
24、mposition,approximate, %Resistivity,Vcmil/ft(Vm)Mean Temperature Coefficient of Resistance, amppm for C Over Temperature Range,D TMaximum Thermal emfversus Copper, mV/CBElongation in 10 in., min, %DT amDT mV/CTemperatureRange, DTCOver0.002in.DinDiameter0.002 to0.001in.DinDiameter0.0009in.DinDiameter
25、and Finer12 3 456789101121a nickel base, nonmagnetic 800 (1.330) 0, 620 +25to55 0,620 + 25 to + 105 + 0.003 65 to + 250 10 5 31b nickel base, nonmagnetic 800 (1.330) 0, 610 +25to55 0,610 + 25 to + 105 + 0.003 65 to + 150 10 5 31c nickel base, nonmagnetic 800 (1.330) 0, 65 +25to55 0,65 + 25 to + 105
26、+ 0.003 65 to + 150 10 5 32a iron base, magnetic 800 (1.330) 0, 620 +25to55 0,6 20 + 25 to + 105 0.004 65 to + 200 10 5 32b iron base, magnetic 800 (1.330) 0, 610 +25to55 0,610 + 25 to + 105 0.004 65 to + 150 10 5 33a 80 nickel, 20 chromium 650 (1.081) + 80, 620 +25to55 +80,620 + 25 to + 105 + 0.006
27、 65 to + 250 15 5 33b 80 nickel, 20 chromium,stabilized675 (1.122) + 60,6 20 +25to55 +60,620 + 25 to + 105 + 0.006 65 to + 250 15 5 34 60 nickel, 16 chromium,balance iron675 (1.122) + 140, 630 + 25 to 55 + 140, 630 + 25 to + 105 + 0.002 65 to + 200 15 5 35a 55 copper, 45 nickel 300 (0.499) 0, 620 +2
28、5to55 0,620 + 25 to + 105 0.045 65 to + 150 15 5 35b 55 copper, 45 nickel 300 (0.499) 0, 640 +25to55 0,640 + 25 to + 105 0.045 65 to + 150 15 5 36 manganin type 290 (0.482) 0, 615EE0, 615EE0.003 + 15 to + 35 15 5 37 77 copper, 23 nickel 180 (0.299) + 180, 630 + 25 to 55 + 180,6 30 + 25 to + 105 0.03
29、7 65 to + 150 15 5 38 70 nickel, 30 iron 125 (0.199) + 3600, 6400 + 25 to 50 + 4300, 6400 + 25 to + 104 0.040 50 to + 100 15 5 39 90 copper, 10 nickel 90 (0.150) + 450, 650 + 25 to 55 + 450, 650 + 25 to + 105 0.026 65 to + 150 15 5 310 94 copper, 6 nickel 60 (0.100) + 700, 6200 + 25 to 55 + 700,6 20
30、0 + 25 to + 105 0.022 65 to + 150 15 5 311 98 copper, 2 nickel 30 (0.050) + 1400, 6300 + 25 to 55 + 1400, 6300 + 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 other classes are for information only.
31、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 plus or minus sign the polarity of the
32、 couple.CThe maximum temperature values listed apply to the alloy wire only. Caution should be exercised pending knowledge of the maximum temperature of use forthecoating material involved.DIf metric sizes are desired, 1 in. = 25.4 mm.EAlloy Class 6 (manganin type for resistors), has a temperature-r
33、esistance curve of parabolic shape with the maximum resistance normally located between 25 and30C. Thus, Columns 5 and 7 cannot indicate 25C as a limit but ammay be expressed as a maximum of + 15 ppm for 15C to the temperature of maximum resistanceand a maximum of 15 ppm from the temperature of maxi
34、mum resistance to 35C. All of the information included in this note is based on measurements made inaccordance with Test Method B84.B26707213. Enamel Coatings13.1 Enamel coatings shall include any baked-on film ofinsulating material, such as varnish enamel, polyurethane,vinyl acetal, etc. and shall
35、conform to the requirementsprescribed in 13.2 to 13.7.13.2 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 recor
36、ding sensitivity of 300 000 V620 % with 150 V across the coating. 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 loose
37、ning of its bond.The surface of the coating shall be smooth 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 t
38、emperatures specified in 13.5 do notrestrict the use of materials 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 fo
39、r 48 h at 100C, after which the enamel shallnot be sufficiently 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
40、off the excess oil.14. Insulated Coverings14.1 Insulated coverings on wire shall include any wrappedtextile covering such as cotton, silk, nylon, glass, etc. It shallinclude both single and double coverings. The second coveringshall be wrapped in the opposite direction from the first.14.2 The insula
41、ting covering shall be wrapped firmly,closely, evenly, and continuously around the wire. It shall befree from voids or bare spots and have a minimum of backtwist. The covering shall be sufficiently closely wrapped sothat, when the wire is bent around a mandrel having a diameterten times the overall
42、diameter of the covered wire, using onlyenough tension to give an even compact layer, the wrappingswill not open enough to make the wire underneath visible to theunaided eye.TABLE 2 Dimensions of Enamel Coated WireANominal Bare Wire Size Light Coated Wire Medium Coated Wire Heavy Coated WireB resist
43、ivity; resistor alloys; resistors;wire woundTABLE 4 Nominal Outside Diameters of Insulated CoveringsANominalBare WireDiameter,in. (mm)NominalDiameterOver Sin-gle Silk orSingle Nylon,in. (mm)NominalDiameterOverDoubleSilk orDoubleNylonin. (mm)NominalDiameterOver Sin-gle Cottonor SingleGlass,in. (mm)No
44、minalDiameterOverDoubleCotton orDoubleGlass,in. (mm)0.0253 0.027 0.0288 0.0300 0.03380.0226 0.024 0.0261 0.0273 0.03110.0201 0.022 0.0236 0.0248 0.02860.0179 0.0197 0.0214 0.0224 0.02640.0159 0.0177 0.0194 0.0204 0.02440.0142 0.0160 0.0177 0.0187 0.02270.0126 0.0144 0.0161 0.0171 0.02110.0113 0.0131
45、 0.0148 0.0158 0.01980.010 0.0118 0.0135 0.0145 0.01850.0089 0.0107 0.0124 0.0134 0.01740.008 0.0098 0.0115 0.0125 0.01650.0071 0.0089 0.0106 0.0116 0.01560.0063 0.0081 0.0098 0.0108 0.01480.0056 0.0074 0.0091 0.0101 0.01410.005 0.0068 0.0085 0.0090 0.01300.0045 0.0063 0.008 0.0085 0.01250.004 0.005
46、8 0.0075 0.0080 0.01200.0035 0.0053 0.007 0.0075 0.01150.0031 0.0049 0.0066 0.0071 0.01110.00275 0.0043 0.0058 . .0.0025 0.0041 0.0055 . .0.00225 0.0038 0.0053 . .0.002 0.0036 0.005 . .0.00175 0.0033 0.0048 . .0.0015 0.003 0.0045 . .0.0014 0.003 0.0044 . .0.0013 0.0029 0.0043 . .0.0012 0.0028 0.0042
47、 . .0.0011 0.0027 0.0041 . .0.001 0.0026 0.0040 . .ATo convert from inches to millimetres multiply by 25.4.TABLE 5 Recommended Maximum Temperatures of Use forCovered WireMaterial Temperature of Use, max, CUncoated Varnish CoatedSilk 90 105Nylon 90 105Cotton 90 105Glass 400A220(polyimide)AThe purchas
48、er should investigate the stability of the wire alloy under thetemperature condition indicated.TABLE 6 Quantities of Wire and Capacities of SpoolsDiameter of Wire, in. (mm)AWeight per Spool,min, lb (kg)BCapacity of Spool,lb (kg)B0.0005 0.004 10.0006 0.01 10.0007 0.015 10.0008 0.025 10.0009 0.035 10.
49、001 0.04 10.0011 0.05 10.0012 0.06 10.0013 0.07 10.0014 0.08 10.0015 0.09 10.00175 to 0.00225 0.10 10.0025 to 0.0031 0.15 10.0035 to 0.0056 0.25 10.0063 to 0.010 0.50 20.0113 to 0.0226 2.50 5ATo convert from inches to millimetres multiply by 25.4.BTo convert from pounds to kilograms multiply by 0.453.TABLE 7 Types and Sizes of SpoolsCapacity ofSpool, lb (kg)ASpool Dimensions, in. (mm)BDiameter ofFlangeTra-verseDiameter of HoleDiameter ofBarrel1212 3 0.635 114 to 1342 3 3 0.635 112 to 25 4 to 412 3 0.635 112 to 3
