Izod and Charpy Impact tests measure a materials resistance to impact at a single point from a swinging pendulum or hammer. The tests can be carried out in a variety of orientations and in notched or un-notched formats.

In the Izod Impact Test, a notched square section specimen is clamped vertically, cantilever fashion, in the impact machine. The pendulum is released and allowed to strike through the specimen. The Izod Impact Strength is the energy needed to initiate fracture and continue until the specimen is broken. Izod specimens are notched on the impact face to prevent deformation of the specimen on impact.

In the Charpy Impact Test, the rectangular section specimen is mounted horizontally without clamping and supported at both ends. The pendulum is released and allowed to strike through the specimen. The Charpy Impact Strength is the energy needed to initiate fracture and continue until the specimen is broken. The specimens can be either notched or un-notched and oriented edgewise or flatwise.

In both impact tests Impact Energy (in joules) and Impact Strength (the ratio of impact energy in joules to the un-notched cross-sectional area, in joules per square metre) are typically quoted for our customers. The higher the number the tougher or more impact resistant the material.

Please contact us to find out how Exova’s Impact laboratory test method can meet your specific requirements.