In the twenty-five years since the first edition of ‘Ultrasonic Flaw Detection by Drury 3^rd Edition for Technicians’ was published, there have been a number of advances in transducer technology and flaw detection instruments. The gradual acceptance by industry that the sizing of weld defects by intensity drop was not as accurate as had been claimed led to the development of the TOFD technique. Modern digital flaw detectors and computer technology allow far more information to be stored by the operator. The author thus felt that it was time to give the book a thorough review and to try to address some of the advances. The result is this new edition.