Intermediate shell for a motor vehicle door, method for producing an intermediate shell, and a door for a motor vehicle

A method for producing an intermediate shell for a side door of a motor vehicle, comprising the steps of:

• producing the intermediate shell in one piece from a metal blank by forging, wherein the intermediate shell includes a lower frame part, a window frame, and a belt line;
• locally adjusting a mechanical strength in the intermediate shell in a region by collecting fibers in the region during the forging, wherein the mechanical strength of the region is greater than a mechanical strength of another region of the intermediate shell;
• and
• forging on the intermediate shell a side impact brace and a connection element.