This unique volume examines 23 peer-reviewed papers that represent the latest worldwide technology in pendulum impact testing. Written by 50 U.S. and international experts in their field, these papers are organized into 4 sections: • Background of Impact Testing • Reference Energies, Machine Stability, and Calibration • Impact Test Procedures • Fracture Toughness Assessment from Impact Test Data STP 1380 marks the 100 year anniversary of the invention of the pendulum impact test by S. Bent Russell, and the research and standardization efforts of G. Charpy during the early part of the 20th century. As an added bonus, reprints of two landmark papers written by Russell and Charpy are included in this volume, describing the development of the test equipment and procedures.