Time-of-flight diffraction (TOFD) transducers and wedges generate refracted longitudinal waves in steel. These highly damped probes provide a high resolution for ultrasonic testing of welds. Sonatest manufactures composite and non-composite TOFD transducers of varying frequencies from 2MHz to 15MHz and crystal diameters ranging from approximately 3mm (0.125″) to 20mm (0.787″). To accompany this range is a wide selection of TOFD wedges manufactured from durable plastic, brass, or stainless steel to suit varying inspection environments.