Extrusion

• A. is extensively used for making bolts and nuts
• B. is used for reducing the diameter of round bars and tubes by rotating dies which open and close rapidly on the work
• C. is used to improve fatigue resistance of the metal by setting up compressive stresses in its surface
• D. consists of pressing the metal inside a chamber to force it out by high pressure through an orifice which is shaped to provide the desired form of the finished part