The Izod impact tester is designed to determine the resistance to impact fracture of materials. The Izod has a pendulum-type hammer which swings down to break a specimen, which often has a notch in it prepared in a special notching machine. The impact strength needed to break the specimen is reported in terms of energy absorbed per unit width of the specimen.

Example

The Izod is used to determine the strength of newly developed polymer systems. The Izod impact strength is often used when studying the mechanical properties of materials and in comparing different samples.