ASTM D4812 : 99

Standard Test Method for Unnotched Cantilever Beam Impact Strength of Plastics

Standard Details

1.1 This test method covers the determination of the resistance to breakage by flexural shock of plastics, as indicated by the energy extracted from standardized (Note 1) pendulum-type hammers, mounted in standardized machines, in breaking standard specimens with one pendulum swing. The result of this test is reported in terms of impact strength per unit of specimen width.

Note 1-The machines with their pendulum-type hammers have been standardized in that they must comply with certain requirements, including a fixed height of hammer fall that results in a substantially fixed velocity of the hammer at the moment of impact. Hammers of different initial energies (produced by varying their effective weights) are recommended for use with specimens of different impact strengths. Moreover, manufacturers of the equipment are permitted to use different lengths and constructions of pendulums (with resulting possible differences in pendulum rigidities (see Section 4), and other differences in machine design).

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 does not purport to address all of the safety problems, 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.