A drop hammer can be found in foundries and factories and shapes metal into heavy steel parts and thin metal stampings. The traditional drop hammer, or press, began as a steam-powered device and has evolved into a hydraulically-powered machine. This machine stamps metal into machine parts, gears and even automobile body and chassis components. Another useful application of the drop hammer or drop forge is the manufacture and creation of hand tools.
The early factory workers used dangerous drop hammers that had none of the modern safety devices found on machines today. Often, the workers would be reaching into a press or drop hammer and the machine would accidentally trip, sending the die crashing down. Workers would often lose fingers, hands and arms, as well as their lives. Those early machines also operated on steam power. The steam escaping from the drop hammers created a hot and dirty work environment, and the advancement to hydraulic power made working on a drop hammer much more bearable.
The basic style of drop hammer does not vary much. A large steel chassis containing changeable dies is lifted by hydraulic rams above a similarly-sized steel chassis containing a reverse image of the upper die. When the press or hammer is in the open position, workers or operators place a sheet of metal into the hammer; when all operators are clear of the dies, each operator pushes a start switch. When all operators have pushed their respective buttons and are holding them down, the machine will trip or switch on, sending the top dies into the bottom dies and stamping a molded piece out of the blank metal.
Once the stamping of the metal is complete, the operators reach in and pull the stamping as well as the scrap out of the dies. A new sheet of metal is placed into the drop hammer and the cycle begins again. On the typical press, the die loaders work on one side of the machine while the part unloaders work on the other side of the press. On very large drop hammers used to create large stampings, the metal being stamped might be loaded into the drop hammer with a crane or a conveyor system. The pressing or stamping capacity of a hammer is rated in US as well as metric tons, with many hammers producing much more than 500 US tons (37 metric tons) of pressing power.