Designation:B452–02
Standard Specification for
Copper-Clad Steel Wire for Electronic Application1
This standard is issued under thefixed designation B452;the number immediately following the designation indicates the year of original adoption or,in the ca of revision,the year of last revision.A number in parenthes indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.
This standard has been approved for u by agencies of the Department of Defen.
1.Scope
1.1This specification covers bare round copper-clad steel wire for electronic application.
1.2Four class of copper-clad steel wire are covered as follows:
1.2.1Class30HS—Nominal30%conductivity hard-drawn,
1.2.2Class30A—Nominal30%conductivity annealed, 1.2.3Class40HS—Nominal40%conductivity hard-drawn,and
1.2.4Class40A—Nominal40%conductivity annealed. 1.3The values stated in inch-pound units are to be regarded as the standard.The values given in parenthes are in SI units.
2.Referenced Documents
2.1The following documents of the issue in effect on the date of material purcha form a part of this specification to the extent referenced herein:
2.2ASTM Standards:
B193Test Method for Resistivity of Electrical Conductor Materials2
B258Specification for Standard Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Ud as Electrical Conductors2
2.3National Institute of Standards and Technology: NBS Handbook100—Copper Wire Tables3
3.Ordering Information
3.1Orders for material under this specification shall include the following information:
3.1.1Quantity of each size and class,
3.1.2Wire size,diameter in inches(e5.3and Table1), 3.1.3Class of wire(e1.2and Table1),
3.1.4Packaging and shipping(Section10),
3.1.5If inspection is required(e6.3.3),and
3.1.6Place of inspection(e6.1).
4.Material
4.1The wire shall consist of a core of homogeneous open-hearth,electric-furnace,or basic-oxygen steel with a continuous outer cladding of copper thoroughly bonded to the core throughout and shall be of such quality as to meet the requirements of this specification(Note1).
N OTE1—The copper-clad steel wire provides a high-strength conductor for u in wire and cable where greater strength is required and a lower conductivity can be tolerated.At high frequencies the reduced conductiv-ity is less pronounced due to concentration of the current in the outer periphery of the wire.Minimum thickness of6%and10%of the radius for30and40%conductivity material,respectively,has been established to facilitate the inspection of thickness onfine wires.
5.General Requirements
5.1Tensile Strength and Elongation—The copper-clad steel wire shall conform to the tensile strength and elongation requirements of Table1.For intermediate sizes not listed in Table1,the elongation requirements of the next smaller size shall apply;in the ca of tensile strength,the requirements of the next larger size shall apply.
5.2Resistivity—The electrical resistivity at a temperature of 20°C shall not exceed the values prescribed in Table2.See Note2for calculating electrical resistance.
N OTE2—Relationships which may be uful in connection with the values of electrical resistivity prescribed in this specification are shown in Table3.Resistivity units are bad on the International Annealed Copper Standard(IACS)adopted by IEC in1913,which is1⁄58V·mm2/m at20°C for100%conductivity.The value of0.017241V·mm2/m and the value of 0.15328V·g/m2at20°C are respectively the international equivalent of volume and weight resistivity of annealed copper equal to100% conductivity.The latter term means that a copper wire1in.in length and weighing1g would have a resistance of0.15328V.This is equivalent to a resistivity value of875.20V·lb/mile2,which signifies the resistance of a copper wire1mile in length weighing1lb.It is also equivalent,for example,to1.7241µV/cm of length of a copper bar1cm2in cross ction.
A complete discussion of this subject is contained in NBS Handbook100. The u offive significantfigures in expressing resistivity does not imply the need for greater accuracy of measurement than that specified in Test Method B193.The u offive significantfigures is required for complete reversible conversion from one t of resistivity units to another.
5.3Dimensions and Permissible Variations—The wire sizes
1This specification is under the jurisdiction of ASTM Committee B01on
Electrical Conductors and is the direct responsibility of Subcommittee B01.06on
Composite Conductors.
Current edition approved April10,2002.Published April2002.Originally
published as B452–67.Last previous edition B452–93(1998)e1.
2Annual Book of ASTM Standards,V ol02.03.
3Available from the National Institute of Standards and Technology(NIST),
Gaithersburg,MD20899.
1
Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.
shall be expresd as the diameter of the wire in decimal fractions of an inch to the nearest0.0001in.(0.003mm)(Note 3).For diameters under0.0100in.(0.254mm),the wire shall not vary from the specifie
d diameter by more than60.0001in.
(0.003mm)and for diameters of0.0100in.(0.254mm)and over,the wire shall not vary from the specified diameter by more than61%,expresd to the nearest0.0001in.(0.003 mm).
N OTE3—The values of the wire diameters in Table1are given to the nearest0.0001in.(0.003mm)and correspond to the standard sizes given in Specification B258.The u of gage numbers to specify wire sizes is not recognized in this specification becau of the possibility of confusion. An excellent discussion of wire gages and related subjects is contained in NBS Handbook100.
5.4Adhesion and Other Defects—The copper-clad steel wire,when tested in accordance with7.4,shall not reveal any ams,pits,slivers,or other imperfection of sufficient magni-tude to indicate inherent defects or imperfections.Examination of the wire at the break with the unaided eye(normal spectacles excepted)shall show no paration of copper from the steel.
5.5Joints—Necessary joints in the wire and rods prior to final drawing shall be made in accordance with good commer-cial practice.Thefinished wire shall contain no joints or splices made atfinished size.
5.6Finish—The wire shall be free from copper discontinui-ties and all imperfections not consistent with good commercial practice(e7.5).
5.7Copper Thickness—The minimum copper thickness due to eccentricity shall be not less than the following:
5.7.1The30%conductivity wire shall have a minimum thickness of not less than6%of the wire radius.
5.7.2The40%conductivity wire shall have a minimum thickness of not less than10%of the wire radius(e7.6and Note3).
6.Inspection
6.1General—All tests and inspections shall be made at the place of manufacture unless otherwi agreed upon between the manufacturer and the purchar at the time of the purcha. The manufacturer shall afford the inspector reprenting the purchar all reasonable facilities to satisfy him that the
TABLE1Tensile and Elongation Requirements
Diameter Cross-Sectional Area at20°C Tensile Strength,psi(kgf/mm2)Elongation,min.
%in10in.
(250mm)
< cmil in.2mm2Class30HS,min Class30A,min Class40HS,min Class40A,min
Class
30HS and
40HS
Class
30A and
40A
0.0720 1.8351800.00407 2.63127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.515 0.0641 1.6341100.00323 2.08127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.515 0.0571 1.4532600.00256 1.65127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.515 0.0508 1.292580
0.00203 1.31127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.515
0.0453 1.1520500.00161 1.04127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.515 0.0403 1.0216200.001280.823127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.015 0.03590.91212900.001010.653127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.015 0.03200.81310200.0008040.519127000(89.3)50000(35.2)110000(77.3)45000(31.6) 1.015
0.02850.7248120.0006380.412127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.015 0.02530.6436400.0005030.324127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.015 0.02260.5745110.0004010.259127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.015 0.02010.5114040.003170.205127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.01790.4553200.0002520.162127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.01590.4042530.0001990.128127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.01420.3612020.0001580.102127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.01260.3201590.0001250.0804127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010
0.01130.2871280.0001000.0647127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.01000.2541000.00007850.0507127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.0089
0.22679.20.00006220.0401127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00800.20364.00.00005030.0324127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00710.18050.40.00003960.025*******(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00630.16039.70.00003120.020*******(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00560.14231.40.00002460.0159127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00500.12725.00.00001960.0127127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010
0.00450.11420.20.00001590.010*******(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00400.10216.00.00001260.00811127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00350.08912.20.000009620.00621127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010 0.00310.0799.610.000007550.00487127000(89.3)55000(38.7)110000(77.3)50000(35.2) 1.010
TABLE2Resistivity,max,at20°C
Class of Wire V·mm2/m
30HS and30A 40HS and40A 0.05862(0.058616) 0.04397
(0.043970)
material is being furnished in accordance with this specifica-tion(Note4).
N OTE4—Cumulative results cured on the product of a single manu-facturer,indicating continued conformance to the criteria,are necessary to ensure an overall product meeting the requirements of this specification. The sample sizes and conformance criteria given for the various charac-teristics are applicable only to lots produced under the conditions. 6.1.1Unless otherwi agreed by the manufacturer and the purchar,conformance of the wire to the various requirements listed in Section5shall be determined on samples taken from each lot of wire prented for acceptance.
6.1.2The manufacturer shall,if requested prior to inspec-tion,certify that all wire in the lot was made under such conditions that the product as a whole conforms to the requirements of this specification as determined by regularly made and recorded tests.
6.2Definitions:
6.2.1lot—any amount of wire of one class and size pre-nted for acceptance at one time,such amount,however,not to exceed10000lb(4500kg)(Note5).
N OTE5—A lot should compri material taken from a product regularly meeting the requirements of this specification.Inspection of individual lots of less than500lb(230kg)of wire cannot be justified economically. For small lots of500lb(230kg)or less,the purchar may agree to the manufacturer’s regular inspection of the product as a whole as evidence of acceptability of such small lots.
6.2.2sample—a quantity of production units(coils,reels, etc.)lected at random from the lot for the purpo of determining conformance of the lot to the requirements of this specification.
6.2.3specimen—a length of wire removed for test purpos from any individual production unit of the sample.
6.3Sample Size—The number of production units in a sample(e Note4)shall be as follows:
6.3.1For tensile strength,elongation,resistivity,and adhe-sion and other defects,the sample shall consist of four production units.For surfacefinish the sampling shall be in accordance with Table4.From each unit,one test specimen of sufficient length shall be removed for the performance of the required tests.
6.3.2For dimensional measurements,the sample shall con-sist of a quantity of production units shown in Table5under heading“First Sample.”
6.3.3For packaging inspection(when specified by the purchar at the time of placing the order),the sample shall consist of a quantity of production units as shown in Table4.
7.Test Methods
7.1Tensile Strength and Elongation—The tensile strength, expresd in pounds per square inch(or kilograms-force per square millimetre),shall be obtained by dividing the maximum load carried by the specimen during the tension test,by the original cross-ctional area of the specimen.Tensile strength and elongation may be determined simultaneously on the same specimen.
7.1.1For Class30A and40A,the elongation of wire may be determined as the permanent increa in length,expresd in percent of the original length,due to the breaking of the wire in tension,measured between gage marks placed originally10 in.(250mm)apart upon the test specimen(Note6).The elongation of wire shall be determined as described above or by measurements made between the jaws of the testing machine.When the latter method is ud,the zero length shall be the distance between the jaws at the start of the tension test when10%of the minimum specified breaking load has been applied and be as near10in.(250mm)as practicable,and the final length shall be the distance between the jaws at the time of rupture.The fracture shall be bet
ween gage marks in the ca of specimens so marked or between the jaws of the testing machine and not clor than1in.(25mm)to either gage mark or either jaw.
N OTE6—It is known that the rate of loading during tension testing affects the performance of the sample to a greater or lesr extent depending upon many factors.In general,tested values of tensile strength are incread and tested values of elongation are reduced with increa of speed of the moving head of the testing machine.In the ca of tests on soft or annealed wire,however,the effects of speed of testing are not pronounced.Tests of soft wire made at speeds of moving head which under no-load conditions are not greater than12in./min(300mm/min)do not alter thefinal results of tensile strength and elongation determinations to any practical extent.In the ca of hard-drawn wire,the effects are pronounced when the speed of the moving head is excessive.It is suggested that tests be made at speeds of moving head which,under no-load conditions,are not greater than3in./min(76mm/min),but in no ca at a speed greater than that at which correct readings can be made.
7.1.2For Class30HS and40HS,the elongation shall be measured by means of an extensometer or other device suitable for measuring elongation in10in.(250mm),and having a vernier reading to0.01in.(0.25mm)attached to the test specimen at a tension load of approximately10%of rated stren
gth.The elongation shall be obrved while applying a tension load to the specimen and the reading when fracture occurs shall be taken as the elongation of the specimen.Tests
TABLE3Equivalent Resistivity Values
Class Volume Conduc-
tivity at20°C,%
IACS Resistivity Equivalents at20°C
Volume Mass
V·mm2/m V·cmil/ftµV·in.µV·cm V·lb/mile2V·g/m2
40A and40HS39.2100.04397026.45 1.7312 4.39702046.30.35836 30A and30HS29.4130.05861635.26 2.3078 5.86162727.80.47772 TABLE4Sampling for Surface Finish and Packaging Inspection
No.of Units in Lot No.of Units
in Sample,n
Allowable No.of Defective Units,c
1to30,incl All0 31to50,incl300 51to100,incl370 101to200,incl400 201to300,incl701 301to500,incl1002 501to800,incl1303 Over800155
4
in which the elongation is less than specified,but in which the fracture has occurred within 1in.(25mm)of the jaws or extensometer clamps,shall be disregarded.
7.2Resistivity —The electrical resistivity of the material shall be determined in accordance with Test Method B 193.7.3Dimensional Measurements —Dimensional measure-ments shall be made with a micrometer caliper equipped with a vernier graduated in 0.0001in.(0.0025mm).Each coil shall be gag
ed at three places,one near each end and one near the middle.From each spool approximately 12ft (3600mm)shall be unreeled and the wire gaged in six places between the cond (600th mm)and twelfth foot (3600th mm)from the end.
7.4Torsion Test —The wire shall withstand without fracture not less than 20torsions in a length equivalent to 100times the nominal diameter of the specimen.All twists shall be made in the same direction.The rate of applying the twists shall be approximately 15/min.Specimens shall be twisted to destruc-tion and shall meet the requirements of 5.4of this specification.7.5Finish —Surface finish inspection shall be made with the unaided eye (normal spectacles excepted).
7.6Copper Thickness —Determination of the minimum copper thickness shall be done by microscopical examination of the polished end or by standard stripping methods or by any other suitable method agreed upon between the manufacturer and the purchar.
8.Conformance Criteria (See Note 4)
8.1Any lot of wire,the samples of which comply with the conformance criteria of this ction,shall be considered as complying with the requirements of Section 5.Individual production units that fail to meet one or more of the require-ments shall be rejected.Failure of a sample group from a lot to meet
one or more of the following criteria shall constitute cau for rejection of the lot.The conformance criteria for each of the prescribed properties given in Section 5are as follows:8.2Tensile Strength and Elongation (for all Class)—The lot shall be considered conforming,if the values of the four specimens are not less than the appropriate values in Table 1.8.3Resistivity —The electrical resistivity of each of the four specimens shall conform to the requirements of Table 2.Failure to meet the requirements shall constitute failure to meet the resistivity conformance criterion of 5.2.
8.4Dimensions —The dimensions of the first sample (Table 4)shall conform to the requirements of 5.3.If there are no failures,the lot shall be considered as conforming to the requirements.If there are failures,but the number of the do
not exceed the allowable defect number c 2(Table 5)for the respective number of units in the sample,a cond sample equal to n 2shall be taken and the total defects of the n 1+n 2units shall not exceed the allowable defect number c 2.Failure to meet this requirement shall constitute failure to meet the dimensional conformance criterion.
8.5Adhesion —Adhesion of the copper cladding to the steel of each of the four specimens shall conform to the require-ments of 5.4.Failure of more than two specimens shall constitute failure to
meet the adhesion criterion.If more than two specimens fail to meet the adhesion criterion,four addi-tional specimens from the lot shall be tested,all of which shall conform to the adhesion criterion.However,any individual production unit from which the specimen failed to meet the adhesion criterion shall be rejected.
8.6Finish —The finish of the samples taken in accordance with Table 5shall conform to the requirements of 5.6.The number of units in the sample showing surface defects not consistent with commercial practice shall not exceed the allowable defect number c,in Table 5.Failure to meet this requirement shall constitute failure to meet the finish conform-ance criterion.
8.7Packaging —Conformance to the packaging require-ments specified by the purchar shall be determined in accordance with Table 5.The number of units in the sample showing nonconformance to the requirements shall not exceed the allowable defect number c ,in Table 4.Failure to meet this requirement shall constitute failure to meet the packaging conformance criterion.
9.Density
9.1For the purpo of calculating mass/unit length,cross ctions,etc.,the density of the wire shall be taken as shown below at 20°C for the material covered by this specification (Note 7).
Product
English Units Metric Units 30%conductivity 0.2944lb/in 38.15g/mm 340%conductivity
0.2975lb/in 3
8.24g/mm 3
N OTE 7—The term mass per unit length is ud in this standard as being more technically correct.It replaces the term weight.
10.Packaging and Shipping
10.1The package size shall be agreed upon by the manu-facturer and the purchar in the placing of individual orders (Note 8).The wire shall be protected against damage in ordinary handling and shipping.
N OTE 8—Attention is called to the desirability for agreement between
TABLE 5Sampling for Dimensional Measurements
No.of Units in Lot
First Sample
Second Sample
No.of Units in Sample,
n 1
Allowable No.of Defects in Sample,c 1
No.of Units in Sample,
n 2
n 1+n 2Allowable No.of Defects in Both Samples,c 2
1to 14,incl .15to 50,.51to 100,incl 19023421101to 200,incl 24046702201to 400,incl 290761053401to 800,incl 3301121454Over 800
34
116
150
4
the manufacturer and the purchar on package sizes which will be sufficiently large and yet not so heavy or bulky that the wire may likely be damaged in handling.
11.Keywords
11.1clad steel electrical conductor;copper electrical conductor—copper-clad steel;copper-clad steel electrical con-ductor;electrical conductor;hard drawn copper-clad steel wire; steel wire—copper-clad
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