Abstract: An axial displacement mechanism for precisely adjusting the axial displacement of a turret plate relative to a turret table is disclosed. Turret tables are commonly used to support a workpiece such as the hollow tubular section of a tin box immediately prior to the seaming of a lid thereto and are commonly angularly indexed between a plurality, usually four, separate work stations disposed above the turret plate. The turret table is rigidly secured to a frame while the turret plate must be capable of being axially displaced relative thereto to suit a variety of different components. The turret plate is rigidly secured to an annular bush through a central aperture of which passes a cylindrical screw, the threads of which engage in corresponding threads in the inner annular surface of the bush. The screw abuts an axially fixed portion secured to or being a drive spindle which imparts motion to said fixed portion, said annular bush and said screw to cause the turret plate to rotate.