A type of gravity-drop A machine that applies a sharp blow to the work area through the fall of a ram onto an anvil. The ram can be driven by gravity or power. See also Gravity Hammer and Power-Driven Hammer. in which 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 an air cylinder. Because the length of stroke can be controlled, ram velocity and therefore the energy delivered to the workpiece can be varied. See also 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. and A class of forging hammer wherein energy for forging is obtained by the mass and velocity of a freely falling ram and the attached upper die. Examples are board hammers and air-lift hammers..