ASTM D256 – 10E1 – For IZOD Pendulum Impact Resistance

ASTM D256 – 10E1 – For IZOD Pendulum Impact Resistance

The kinetic energy that is required to initiate fracture and continue fracture until the specimen is broken is IZOD impact. The IZOD Impact testing is used to understand the notch sensitivity in plastics, complies with ASTM D256 standard test method. Made reference to the specification of the material being tested prior to proceeding with the test methods. Give priority to the preparation of test sample, dimensions, conditioning, and testing parameters included in the material specification. Default conditions are applicable if the material specification is not available.

The pendulum impact test is used to determine the energy required to break the standard test sample of a specific size. This is the single point test measuring a material resistance to impact from a swinging pendulum. The specimen is notched so that it could not deform the IZOD specimen when the impact is used. The test method provides easy and quick quality control inspection and determines the impact properties of the materials and compares for the general rigidity.

Test Procedure for IZOD Impact Testing


During the testing procedure, the test specimen is clamped into pendulum impact test fixture where the notched side is facing the striking edge of the pendulum, which is released to strike through the sample. The heavy hammer can be used if breakage does not occur after the first strike. It is better to perform the test at temperatures simulating the intended end use environment because many materials indicate lower impact strength at low temperatures such as thermoplastics.

The standard size of the specimen is 64 x 12.7 x 3.2 mm (2½ x ½ x 1/8 inch) with thickness 3.2 mm (0.125 inches). However, the preferred thickness is 6.4 mm (0.25 inch) as it is may not bend or crush.

Notch Cutter for Impact Tester

Presto’s notch cutter is utilized to make a notch in the IZOD samples as per ASTM D256-10 standard test method. The machine has an outer body that is neatly powder coated with a balanced base.