6.1 Tension tests, properly interpreted, provide information with regard to the tensile properties of rigid tubing, when employed under conditions approximating those under which the tests are made. It is possible that the tensile strength values will vary with the size of the tube and with the temperature and atmospheric conditions. Tension tests provide data potentially useful for research and development and for engineering design, and quality control purposes.

1.1 These test methods cover the testing of rigid tubes used in electrical insulation. These tubes include many types made from fibrous sheets of basic materials, such as cellulose, glass, or nylon, in the form of paper, woven fabrics, or mats, bonded together by natural or synthetic resins or by adhesives. Such tubes include vulcanized fiber and thermosetting laminates, as well as tubes made from cast, molded, or extruded natural or synthetic resins, with or without fillers or reinforcing materials.

1.2 Tubes tested by these test methods are most commonly circular in cross section; however, noncircular shapes are also in commercial use. To the extent that the individual methods are compatible with a particular noncircular shape, these test methods are applicable to these other shapes. For tests on noncircular tubes, appropriate comments shall be included in the test report, including details of orientation of test specimens with respect to the cross section of the tube.

1.3 The procedures appear in the following sections:

1.4 The values stated in inch-pound units are to be regarded as the standard. SI units in parentheses are for information only.

1.5 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. For a specific hazard statement, see 27.1.1.