PURPOSE: To increase the pressing force of the dies, and to diminish the noise, by substituting the anvil for the large diameter roller which is installed in the inner wall of housing of the rotary swaging machine and is contacting with the small diameter roller of the backer.

CONSTITUTION: The anvils 5 are fixed to inside of the housing 1 at uniform interval; and the backers 3 provided with small diameter rollers 4 are radially arranged within the anvils 5. The dies 7 are radially installed within the backers 3 through the wedge pieces 6. Each of backers 3 and dies 7 is held by the rotary guide parts 8, and is rotated through the pulley 9 attached to the end of the parts 8. If the roller 4 contacts against the inner wall of the anvil 5, the roller 4 moves inward, and the dies also move through the backer; here-by, the material 10 placed at the central portion is formed while being moved in the direction 11.