Information on the most widely used ASTM standards within the materials testing industry
ISO 8256:2023 Plastics — Determination of tensile-impact strength
ISO 8256 specifies two methods (method A and method B) for the determination of the tensile-impact strength of plastics under defined conditions. The tests can be described as tensile tests at relatively high strain rates. These methods can be used for rigid materials (as defined in ISO 472), but are especially useful for materials too flexible or too thin to be tested with impact tests conforming to ISO 179 or ISO 180.These methods are used for investigating the behaviour of specified specimens under specified impact velocities, and for estimating the brittleness or the toughness of specimens within the limitations inherent in the test conditions.
These methods are applicable both to specimens prepared from moulding materials and to specimens taken from finished or semi-finished products (for example mouldings, films, laminates, or extruded or cast sheets).

Results obtained by testing moulded specimens of different dimensions may not necessarily be the same. Equally, specimens cut from moulded products may not give the same results as specimens of the same dimensions moulded directly from the material. Test results obtained from specimens prepared from moulding compounds cannot be applied directly to mouldings of any given shape, because values may depend on the design of the moulding and the moulding conditions. Results obtained by method A and method B may or may not be comparable.
Scope:
The tensile impact test measures the amount of force needed to break a specimen under a high speed tensile load introduced through a swinging pendulum.
With a fixture 60g, and 120g.
Test Procedure:
1, The thickness and width of the test specimen is recorded.
2, The specimen is then clamped to the crosshead and placed into the pendulum.
3, The pendulum is released and allowed to strike the anvil breaking the specimen.
4, The tensile impact energy is recorded and then corrected impact energy is calculated.
Specimen size:
There are two types of test specimens which can be used, long (L) and short (S). Both are 63.5mm (2.5") long, but gauge length areas vary.
| Type L specimens | with a gauge length of 9.53mm (0.375") provide a greater differentiation between materials. |
| Type S specimens | which have no true gauge length (see the picture above) provide a greater occurrence of brittle failures. |
Require More Customized Solutions?