Abstract: A radially expansible press plunge comprising two main parts named formation part (1) and expansion part (2) which are movable in relation to each other, and in which the expansion part (2) is arranged to provide an expansion of at least some part (16) of the press plunge when the said main parts (1, 2) are moved together, and in which the expansion part (2) comprises a cup formed expansion body (16), and in which the formation part (1) is designed with a formation surface (12) against which at least parts of the expansion body (16) is adapted to slide when the formation part (1) and the expansion part (2) are moved axially towards each other, and in which the expansion part (2) is materially composed of two different portions, namely an outer press portion (19) for executing the actual radially outwards directed contact pressure of the press plunge and consisting of a wear resistant, temperature resistant and elastic material, and an inner carrier portion (20) of a relatively hard, elastic material, preferab