Astm D 4812 – 99 pdf free download

Standard Test Method for
Unnotched Cantilever Beam Impact Resistance of Plastics1

This standard is issued under the fixed designation D 4812; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of the last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope

1.1 This test method covers the determination of the resistance of plastics to breakage by flexural shock, as indicated by
the energy extracted from standardized pendulum-type hammers, mounted in standardized machines, in breaking the standard
specimens with one pendulum swing. The result of this test
the method is reported as the energy absorbed per unit of specimen
width.
NOTE 1—The pendulum-type test instruments 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. Pendulums 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 is permitted to use different lengths and constructions of
pendulums (with resulting possible differences in pendulum rigidities (see
Section 5), 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 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.
NOTE 2—This standard and ISO 180, Method 1U, are similar in content
but are not technically equivalent.

2. Referenced Documents

2.1 ASTM Standards:
D 256 Test Methods for Impact Resistance of Plastics and
Electrical Insulating Materials2
D 618 Practice for Conditioning Plastics and Electrical
Insulating Materials for Testing2
D 883 Terminology Relating to Plastics2
D 5947 Test Methods for Physical Dimensions of Solid
Plastic Specimens3