Abstract: A piston and cylinder assembly for use in actuating a locating pin for sheet metal provides stability for a pin mounted thereon against side to side movement and rotation. To this end the assembly includes a cylinder body assembly with an internal bore and a piston axially slidable within the bore. A piston rod is connected with the piston, and the rod has a free end for connection of a sheet metal locating pin. A first guide surface is formed within the cylinder body assembly and a second guide surface is formed on one of the piston and piston rod, the first and second guide surfaces cooperating to prevent rotation of the piston and piston rod as the piston and piston rod slide axially with respect to the cylinder body assembly. The first and second guide surfaces preferable are internal and external splines. First and second bearings are connected to the cylinder body assembly and support the piston rod for straight line movement. The first and second bearings being located on opposite sides of the piston.