Abstract: A mechanically driven power press has vertical slide mechanism adapted to engage and reciprocate the upper movable element of a die set. Means for adjusting the shut height of said slide including a cylinder secured to said slide and a piston slidable therein and having threaded connection with a portion of said cylinder for shut height adjustment. An hydraulic chamber operable to effect working strokes of said slide. The shut height adjustment has a second threaded portion whereby when said first cylinder is pressurized the threaded parts in engagement with the threaded portion of the piston are forced apart to eliminate thread clearance and lock the shut height adjustment.