Technological progress has required the development of new or improved materials which in turn have necessitated new techniques for their fabrication. The physicist has contributed largely to the successful application of the newer processes such as hydrostatic forming which offers significant advantages in the cold extrusion, upsetting, bulging, etc., of the more difficult and brittle materials, explosive forming which permits the economical production of large and complex shapes, and electrohydraulic and magnetic forming which can facilitate the manufacture of small but complex parts from sheet and tube. The rapid acceleration, by the sudden expansion of gases, of the moving parts of more conventional type machines has been exploited in a number of forming applications. The scope and limitations of these processes are briefly indicated. The application of ultrasonic vibration is said to facilitate the forming of certain metals by reducing the frictional forces and this aspect is receiving increasing attention.