ASTM C366/C366M-16

5.1 Normally, a close tolerance is desirable for core thickness so that sandwich panels may be manufactured with all the sandwich components fitting properly and without crushing the core.

5.2 These test methods are designed for measuring thickness of core as it is produced and are not intended for use in determining dimensions of core specimens for other tests.

5.3 These test methods provide standard methods of obtaining the core thickness of flat sandwich core materials, and provide a basis for determining average thickness dimensions. The thickness properties derived may be used in design properties, material specifications, research and development applications, and quality assurance.

5.4 Factors that influence core thickness measurement and shall therefore be reported include the following: core material through-thickness rigidity, surface roughness, specimen geometry (including warpage), specimen preparation, methods of dimensional measurement, specimen conditioning, and moisture content during dimensional measurements.

1.1 These test methods cover plant manufacturing procedures for measuring the thickness of flat sandwich cores. Permissible core material forms include those with continuous bonding surfaces (such as balsa wood and foams) as well as those with discontinuous bonding surfaces (such as honeycomb). The two test methods covered include the following:

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.3 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.