A compact 50-Joule Charpy impact tester suitable for non-ferrous and low-carbon steels as well as plastics. The machine has an integral safety guard as standard and the operator must use both hands to release the pendulum. It also has a pendulum brake. In its raised position the pendulum has a definite potential energy which changes to kinetic energy during its swing. The pendulum achieves maximum kinetic energy at its lowest swing position, just before it hits the test specimen. The difference between the height of drop before rupture and the height of rise after rupture indicates the impact energy absorbed by the specimen. A scale (calibrated in Joules) shows the energy.