These test methods describe notched-bar impact testing of metallic materials by the Charpy (simple-beam) test and the Izod (cantilever-beam) test. They give the requirements for: test specimens, test procedures, test reports, test machines verifying Charpy impact machines， optional test specimen configurations, precracking Charpy V-notch specimens, designation of test specimen orientation , and determining the percent of shear fracture on the surface of broken impact specimens. In addition, information is provided on the significance of notched-bar impact testing methods of measuring the center of strike.

The essential features of an impact test are: a suitable specimen (specimens of several different types are recognized), a set of anvils, and specimen supports on which the test specimen is placed to receive the blow of the moving mass, a moving mass that has sufficient energy to break the specimen placed in its path, and a device for measuring the energy absorbed by the broken specimen.