1、Designation:B42809(Reapproved 2013)Standard Test Method forAngle of Twist in Rectangular and Square Copper andCopper Alloy Tube1This standard is issued under the fixed designation B428;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,
2、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 U.S.Department of Defense.1.Scope1.1 This test method establish
3、es the requirements for thedetermination of the angle of twist in rectangular and squarecopper and copper alloy tube.1.2 The values stated in inch-pound units are to be regardedas standard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of
4、 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 limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2B846 Terminology for Copper
5、and Copper Alloys3.Terminology3.1 For definitions of terms related to copper and copperalloys,refer to Terminology B846.4.Significance and Use4.1 The rectangular or square copper alloy tube covered bythis test method may be used in applications in which controlof twist is important to proper fit in
6、final assembly and tominimize rework to bring the tube into compliance.It isrecognized that the amount of twist,in degrees,per incrementof length can change as a result of the weight of the productand its length during measurement.4.2 This test method provides a procedure for measuring thetwist in s
7、quare and rectangular copper and copper alloy tubesas a measure of the deviation from straightness.4.3 This test method allows the purchaser and supplier ormanufacturer to inspect square and rectangular copper andcopper alloy tube with a standard technique that providesacceptable twist in delivered
8、tubes.5.Apparatus5.1 Horizontal Reference Plane(see Fig.1(a)and(b)ofsufficient length to support the tube specimen and a clampingdevice to hold one end of the specimen against the referenceplane.5.2 Transparent Plastic Protractor Segment engraved withangle lines as shown in Fig.1(c).5.3 Parallel Fac
9、e Blocks.6.Test Specimen6.1 The test specimen shall be cut to a minimum length of10 in.and a maximum length of 15 in.7.Procedure7.1 Place the tube specimen lengthwise on the referenceplane.Whenever the specimen has noticeable edgewisecurvature,place the specimen so that a side having convexcurvature
10、 is in contact with the reference plane.Furtherplacement requirements are as follows:7.1.1 For rectangular tube,place a major outer dimensionside(width side)against the reference plane,as shown in Fig.1(a).7.1.2 For square tube,having curvature along all edges,place the specimen so that the side wit
11、h the least convexcurvature is against the reference plane.7.2 Clamp one end of the specimen so that the tube surface,adjacent to that end and facing the reference plane,will be infirm contact with this plane.Keep the other end of thespecimen free.7.3 Position the protractor segment flush against th
12、e freeend of the specimen,as shown in Fig.1(b),and measure the1This test method is under the jurisdiction of ASTM Committee B05 on Copperand Copper Alloys and is the direct responsibility of Subcommittee B05.06 onMethods of Test.Current edition approved Oct.1,2013.Published November 2013.Originallya
13、pproved in 1965.Last previous edition approved in 2009 as B428 09.DOI:10.1520/B0428-09R13.2For 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 Summary
14、page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 total angle of twist by reading the degrees for that angle linewhich most nearly coincide with the lower outside edge of thetube end.In making this reading,keep the l
15、ower edge of theprotractor segment in contact with the reference plane or holdit parallel to this plane by use of the parallel face blocks.7.4 The angle of twist per unit length is the total angle oftwist for the specimen divided by its length and shall becalculated according to the units required b
16、y the productspecification.8.Precision and Bias8.1 This test method is unaffected by edgewise curvature ofthe specimen,and the precision for measurement of total angleof twist is 60.5.8.2 This test method has no bias because the values of twistare a direct measurement based on the accuracy of theprotractor and the observation of the operator.9.Keywords9.1 angle of twist;copper;copper alloy;rectangular tube;square tube;twistFIG.1 Horizontal Reference Plane(a),(b)and Transparent Plastic Protractor
