A Hammer delivers forging energy by forcing dies together at relatively high velocity. A guided ram, driven by gravity and/or pneumatic, hydraulic, or steam pressure, executes a forging strike expending the available energy to deform the workpiece, typically in a series of repeated blows, until the final desired shape is achieved at complete die closure, where dies faces meet. Hammers are typically more effective for smaller quantity production where repeated blows allow a smaller capacity forging machine to perform significant deformation due to the accumulation of dimensional change through repeated forging strikes.
A Mechanical Forging Press delivers energy by forcing dies together at relatively lower velocities. A guided ram is linked by hard mechanical connections to a crankshaft, with energy provided by a motorized flywheel. Like a hammer, a stroke or cycle of the press forces dies together against a workpiece, however, the stoke is limited by the hard mechanical linkages and the cycle must be set to achieve full die closure in a single stroke. Mechanical Presses are more suitable for higher volume work and are more easily automated.
Variations of hammer and press design exist to blend strengths or compensate for weakness of each technique of delivering forging energy. Screw presses, hydraulic presses and variations to the typical crankshaft configuration are examples of press designs that achieve improved process results in specific applications. Counterblow hammers and high energy rate impact forging machines are variations of systems that effectively deliver deformation energy in production of unique alloys or configurations.