Patent ID: 7225658

Claim:
Method for manufacture of a cup that is designed to serve as a blank in the production of a metal shell, which method comprises the following stages: a) providing a body of a bar material having a through hole; b) placing the body in a counterdie so that a first end surface of the body that is substantially perpendicular to the central axis of the body is placed facing towards a bottom of the counterdie while the inner wall of the counterdie encloses at least a part of the body, so that the body is hereby placed in the counterdie, the counterdie having a hole in the bottom; c) applying a mandrel to a second end surface of the body that is substantially perpendicular to the central axis of the body, in which the mandrel has a centrally placed guide pin for interacting with the through hole of the body and for interacting with the hole in the bottom of the counterdie so that the body is thereby centered in relation to the mandrel and in relation to the counterdie; d) application of a pressing force to the mandrel, so that the body is cold flow pressed into a cup by plastic deformation, wherein the hole of the counterdie has a shape and dimension that corresponds to a shape and dimension of the guide pin such that the bar material is prevented from flowing between the guide pin and the hole in the counterdie during the application of pressing force to the mandrel.