During the process of steel production, the flaws in steel casting are detected by ultrasonic vibrations. Ultrasonic vibrations are sound waves that have a frequency higher than human hearing. These sound waves are sent through a steel casting such as a part of a machine engine. If there are any flaws in the casting, the quality controller will be able to pinpoint where the flaw is and to determine the flaw's shape and size. This technology is integral to the manufacture of structurally sound steel castings
