For hydrocarbon resins, softening does not take place at a definite temperature. As the temperature rises, these materials gradually change from brittle solids or very viscous liquids to less viscous liquids. For this reason, determination of the softening point must be made by a fixed, arbitrary, and closely defined method if the results obtained are to be comparable.

1.1 These test methods are intended for determining the softening point of hydrocarbon resins and similar materials by means of an automated ring-and-ball apparatus. Portions are similar in technical content to the automated-apparatus versions of Test Methods D 36, E 28, and ISO 4625.

1.1.1 The ring-and-ball softening point of a hydrocarbon resin may also be determined with lower precision using the manual ring-and-ball softening point procedure in Test Methods E 28.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 This standard method 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.