Method for manufacturing a metal packaging in the form of a bottle

A method for manufacturing a bottle-shaped metal packaging, said metal packaging having a body connected to a threaded neck through a shoulder, said method comprising:

• a step of manufacturing a preform including a tubular part, defining a longitudinal axis and a free, downstream edge, wherein said tubular part is connected to a body through a shoulder, and
• a step of forming said tubular part, to form said threaded neck,
• said forming step comprising forming operations suitable to form one-piece structures on said tubular part:
• an operation of forming a roll within a downstream strip of said tubular part, ended by said downstream edge, to form the roll at the downstream edge of the threaded neck,
• an operation of forming a thread within an intermediate strip of said tubular part, and
• an operation of forming a transport ring within an upstream strip of said tubular part, on the shoulder side, configured to cooperate with a handling device,
• wherein said manufacturing method comprises, prior to at least said roll forming operation, a localised annealing step that is carried out in order to provide an annealed state to the tubular part, at least over a height of the downstream strip of said tubular part,
• wherein the localised annealing step is executed to provide the annealed state:
• only at said downstream strip, or
• only at the downstream strip and the upstream strip, in such a way as to keep at least part of a height of the intermediate strip in non-annealed state.