Manufacture of pot-form workpiece

摘要

At least one recess (14,15) is used for reduction of the material thickness. The recess is formed on the initial workpiece (9) in the transition area between the cylinder wall section (12) to be formed and the bottom section (11). The recesses may be formed in the bottom section, or one recess may be provided in the place at which the inner corner between the bottom section and cylinder wall section is formed, and one recess may be formed on the outer side of the bottom section.