A type of A term generally applied to forging hammers wherein energy for forging is provided by gravity, steam, or compressed air. See also Air-Lift Hammer, Board Hammer, Steam Hammer. where the The main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened. is raised for each The vertical movement of a ram during half of the cycle, from the full open to the full closed position or vice versa. by a double-action steam cylinder and the energy delivered to the workpiece is supplied by the velocity and weight of the ram and attached upper The machined recess in a die that gives the forging its shape. driven downward by steam pressure. Energy delivered during each stroke may be varied.