Power hammers are mechanical forging

Forging

Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging. Forged parts can range in weight from less than a kilogram to 580 metric tons...

 hammers that use a non-muscular power source to raise the hammer preparatory to striking, and accelerate it onto the work being hammered. Also called "Open Die Power Forging Hammers." They have been used by blacksmiths, bladesmith

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 woodworking for knife and sword handles, and often...

s, metalworkers, and manufacturers since the late 1880s.

Design and operation

A typical power hammer consists of a frame, an anvil

Anvil

An anvil is a basic tool, a block with a hard surface on which another object is struck. The inertia of the anvil allows the energy of the striking tool to be transferred to the work piece. In most cases the anvil is used as a forging tool...

, and a reciprocating ram holding a hammer head

Hammerhead

- Fiction :* Hammerheads, a 1990 book by Dale Brown.* Hammerhead, a 1964 Charles Hood secret agent novel by James Mayo* Hammerhead , a 1968 film based on the novel by James Mayo* Hammerhead , a 1987 Italian action film...

 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 trip hammer

Trip hammer

A trip hammer, also known as a helve hammer, is a massive powered hammer used in:* agriculture to facilitate the labor of pounding, decorticating and polishing of grain;...

, differing in that the power hammer stores potential energy

Potential energy

In physics, potential energy is the energy stored in a body or in a system due to its position in a force field or due to its configuration. The SI unit of measure for energy and work is the Joule...

 in an arrangement of mechanical linkages and springs, in compressed air

Compressed air

Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....

, or steam

Steam

Steam is the technical term for water vapor, the gaseous phase of water, which is formed when water boils. In common language it is often used to refer to the visible mist of water droplets formed as this water vapor condenses in the presence of cooler air...

, and by the fact that it accelerates the ram on the downward stroke. This provides more force than simply allowing the weight to fall. Earlier designs like trim hammer, steam drop hammer

Steam hammer

A steam hammer is a power-driven hammer used to shape forgings. It consists of a hammer-like piston located within a cylinder. The hammer is raised by the pressure of steam injected into the lower part of a cylinder and falls down with a force by removing the steam. Usually, the hammer is made to...

s, board or strap hammers, use the power source to raise the ram, but let its fall be propelled solely by 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 125 short ton.

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. Locomotive works was one location such large hammers were needed. 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 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

Line shaft

A line shaft is a power transmission system used extensively during the Industrial Revolution. Prior to the widespread use of electric motors small enough to be connected directly to each piece of machinery, line shafting was used to distribute power from a large central power source to machinery...

 flat belt

Belt (mechanical)

A belt is a loop of flexible material used to link two or more rotating shafts mechanically. Belts may be used as a source of motion, to transmit power efficiently, or to track relative movement. Belts are looped over pulleys. In a two pulley system, the belt can either drive the pulleys in the...

 systems or later electric motor

Electric motor

An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...

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

History

Steam and mechanical power hammers were made into the middle of the 20th century in the USA. 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.

Further reading

• Freund, Douglas, Pounding Out The Profits, Mingus Mountain Machine Works, Jerome AZ, 1997 isbn 0-9657652-0-2

External links

• Power hammer at the East Broad Top Railroad