ASTM B428-93(2004)

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
e1
Designation:B 428–93 (Reapproved 1998) 2004)
Standard Test Method for
Angle of Twist in Rectangular and Square Copper and
Copper Alloy Tube
This standard is issued under the fixed designation B 428; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript 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.
e NOTE—Fig. 1 has been editorially changed.
1. Scope
1.1 This test method establishes the requirements for the determination of the angle of twist in rectangular and square copper
and copper alloy tube.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Significance and Use
2.1 The rectangular or square copper alloy tube covered by this test method may be used in applications in which control of
twist is important to proper fit in final assembly and to minimize rework to bring the tube into compliance. It is recognized that
the amount of twist, in degrees, per increment of length can change as a result of the weight of the product and its length during
measurement.
2.2 This test method provides a procedure for measuring the twist in square and rectangular copper and copper alloy tubes as
a measure of the deviation from straightness.
2.3 This test method allows the purchaser and supplier or manufacturer to inspect square and rectangular copper and copper
alloy tube with a standard technique that provides acceptable twist in delivered tubes.
3. Apparatus
3.1 Horizontal Reference Plane (see Fig. 1 and Fig. 2) of sufficient length to support the tube specimen and a clamping device
to hold one end of the specimen against the reference plane.
3.2 Transparent Plastic Protractor Segment engraved with angle lines as shown in Fig. 3.
3.3 Parallel Face Blocks.
4. Procedure
4.1 Placethetubespecimenlengthwiseonthereferenceplane.Wheneverthespecimenhasnoticeableedgewisecurvature,place
the specimen so that a side having convex curvature is in contact with the reference plane. Further placement requirements are as
follows:
4.1.1 For rectangular tube, place a major outer dimension side (width side) against the reference plane, as shown in Fig. 1.
4.1.2 For square tube, having curvature along all edges, place the specimen so that the side with the least convex curvature is
against the reference plane.
4.2 Clamp one end of the specimen so that the tube surface, adjacent to that end and facing the reference plane, w
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