4 artist blacksmith forging with power hammer

Power hammers are mechanical

forging Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at which ...

hammers that use an electrical power source or steam to raise the hammer preparatory to striking, and accelerate it onto the work being hammered. They are also called open die power forging hammers. They have been used by

blacksmith A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such as gates, gr ...

bladesmith Bladesmithing is the art of making knives, swords, daggers and other blades using a forge, hammer, anvil, and other smithing tools. Bladesmiths employ a variety of metalworking techniques similar to those used by blacksmiths, as well as woodwor ...

s, metalworkers, and manufacturers since the late 1880s, having replaced

trip hammer A trip hammer, also known as a tilt hammer or helve hammer, is a massive powered hammer. Traditional uses of trip hammers include pounding, wikt:decorticate, decorticating and polishing of grain in agriculture. In mining, trip hammers were used f ...

Design and operation

A typical power hammer consists of a frame, an

anvil An anvil is a metalworking tool consisting of a large block of metal (usually forged or cast steel), with a flattened top surface, upon which another object is struck (or "worked"). Anvils are as massive as practical, because the higher ...

, and a reciprocating ram holding a hammer head or die. The workpiece is placed on the lower anvil or die and the head or upper die strikes the workpiece. The power hammer is a direct descendant of the

, differing in that the power hammer stores

potential energy In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. Common types of potential energy include the gravitational potenti ...

in an arrangement of mechanical linkages and springs, in

compressed air Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, an ...

, or

steam Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporizatio ...

, and by the fact that it accelerates the ram on the downward stroke. This provides more force than simply allowing the weight to fall. Predecessors like trip hammers, steam drop hammers, board or strap hammers, used the power source to raise the ram or hammer head, but let it fall solely under gravity. Power hammers are rated by weight of moving parts that act directly on the work piece. This includes the weight of the parts that may consist of upper die, ram, mechanical linkage arms and spring(s) or ram, piston, and associated connecting rod(s). Specific design elements are dictated by the power source. The largest power hammer was powered by steam and was rated at .

Types

Power hammers are generally categorized by their power source.

Steam

Steam hammers use steam to drive the hammer. These tended to be the largest models as the great energy of steam was needed to operate them. A locomotive works was one location where such large hammers were needed and the workpieces were sometimes so large it required an overhead crane and several men to position the piece in the hammer, and a man to operate the machine.

Mechanical

These hammers tended to be smaller and were operated by a single man both holding the workpiece and operating the machine. The majority of these mechanical linkage machines were powered by

line shaft A line shaft is a power-driven rotating shaft for power transmission that was used extensively from the Industrial Revolution until the early 20th century. Prior to the widespread use of electric motors small enough to be connected directly t ...

flat belt A belt is a loop of flexible material used to link two or more rotating shafts mechanically, most often parallel. Belts may be used as a source of motion, to transmit power efficiently or to track relative movement. Belts are looped over pulleys ...

systems or later

electric motor An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate f ...

s that rotated a crank on the machine that drove the ram.

Air

Air-power hammers use

pneumatics Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air. Pneumatic systems used in industry are commonly powered by compressed air or compressed inert gases. A centrally located and e ...

to drive the hammer.

History

Steam and mechanical power hammers were made into the middle of the 20th century in the United States. At the end of the 19th century the mechanical power hammer became popular in smaller blacksmith and repair shops. These machines were typically rated between 25 and 500 pounds of falling weight. Many may still be seen in use in small manufacturing and artist-blacksmith shops today. In the middle of the 20th century power hammers driven by compressed air began to gain popularity and several manufacturers are currently producing these hammers today.

References

External links

Power hammer at the East Broad Top Railroad
{{DEFAULTSORT:Power Hammer Hammers Metalworking tools Articles containing video clips