a press for the hydrostatic extrusion of metallic billets to form tubes and other profiles includes a hollow high pressure cylinder having a removable liner which forms the inner wall thereof and which encloses the internal pressure chamber . to protect the removable liner from fatigue breakdown , the inner wall of the liner is coated with a protective coating of an organic polymer and a metallic tube is located adjacent the protective coating and concentric therewith , between the protective coating and the internal pressure chamber .