A jackhammer is a pneumatic tool
Pneumatic tool
A pneumatic tool or air tools is a tool driven by a gas, usually compressed air supplied by a gas compressor. Pneumatic tools can also be driven by compressed carbon dioxide stored in small cylinders allowing for portability...

 that combines a hammer
A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

 directly with a chisel
A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...

 that was invented by Charles Brady King
Charles Brady King
]]Charles Brady King was an American engineer & entrepreneur remembered as an automotive pioneer, artist, etcher, musician, poet, architect, mystic, industrialist and inventor....

. Hand-held jackhammers are typically powered by 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....

, but some use 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. Larger jackhammers, such as rig mounted hammers used on construction machinery, are usually hydraulically powered. They are usually used to break up rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...

, pavement
Pavement (material)
Road surface or pavement is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past cobblestones and granite setts were extensively used, but these surfaces have mostly been replaced by asphalt or concrete. Such...

, and concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

. In modern terminology, a "jackhammer" does not have the capacity to drill rock.

A jackhammer operates by driving an internal hammer up and down. The hammer is first driven down to strike the back of the bit and then back up to return the hammer to the original position to repeat the cycle. The bit usually recovers from the stroke by means of a spring
Spring (device)
A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...

. The effectiveness of the jackhammer is dependent on how much force is applied to the tool.


Pneumatic drills were developed in response to the needs of mining, quarrying, excavating, and tunneling. The first "percussion drill" was made in 1848 and patented in 1849 by Jonathan J. Couch of Philadelphia, Pennsylvania. In this drill, the drill bit passed through the piston of a steam engine. The piston snagged the drill bit and hurled it against the rock face. It was an experimental model. In 1849, Couch's assistant, Joseph W. Fowle, filed a caveat
Patent caveat
A patent caveat was a legal document filed with the United States Patent Office. Caveats were instituted by the US Patent Act of 1836, but were discontinued in 1909. A caveat was like a patent application with a description of an invention and drawings, but without claims. It was an official...

 for a percussion drill of his own design. In Fowle’s drill, the drill bit was connected directly to the piston in the steam cylinder; specifically, the drill bit was connected to the piston’s crosshead. The drill also had a mechanism for turning the drill bit around its axis between strokes and for advancing the drill as the hole deepened. By 1850 or 1851, Fowle was using compressed air to drive his drill, making it the first true pneumatic drill.

The demand for pneumatic drills was driven especially by miners and tunnelers because steam engines required fires in order to operate and the ventilation in mines and tunnels was inadequate to vent the fires' fumes; there was also no way to convey steam over long distances (e.g., from the surface to the bottom of a mine); furthermore, mines and tunnels occasionally contained flammable explosive gases such as methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

. By contrast, compressed air could be conveyed over long distances without loss of its energy, and after the compressed air had been used to power equipment, it could still serve to ventilate a mine or tunnel.

In Europe since the late 1840s, the king of Sardinia
Kingdom of Sardinia
The Kingdom of Sardinia consisted of the island of Sardinia first as a part of the Crown of Aragon and subsequently the Spanish Empire , and second as a part of the composite state of the House of Savoy . Its capital was originally Cagliari, in the south of the island, and later Turin, on the...

, Carlo Alberto
Charles Albert of Sardinia
Charles Albert was the King of Piedmont-Sardinia from 1831 to 1849. He succeeded his distant cousin Charles Felix, and his name is bound with the first Italian statute and the First War of Independence...

, had been contemplating the excavation of a 12 kilometres (7.5 mi) tunnel through Mount Fréjus
Fréjus Rail Tunnel
The Fréjus Rail Tunnel is a rail tunnel of length in the European Alps, carrying the Turin–Modane railway through Mount Cenis to an end on connection with the Culoz–Modane railway and linking Modane, France and Bardonecchia, Italy...

 in order to create a rail link between Italy and France, which would cross his realm. The need for a mechanical rock drill was obvious and this sparked research on pneumatic rock drills in Europe. A Frenchman, Cavé, designed, and in 1851 patented, a rock drill that used compressed air; however, the air had to be admitted manually to the cylinder during each stroke, so it was not successful. In 1854, in England, Thomas Bartlett made and then patented (1855) a rock drill in which the drill bit was connected directly to the piston of a steam engine. In 1855 Bartlett demonstrated his drill, powered by compressed air, to officials of the Mt. Fréjus tunnel project. (In 1855, a German, Schumann, invented a similar pneumatic rock drill in Freiburg, Germany.) Bartlett’s drill was refined by the Savoy
Savoy is a region of France. It comprises roughly the territory of the Western Alps situated between Lake Geneva in the north and Monaco and the Mediterranean coast in the south....

-born engineer Germain Sommeiller
Germain Sommeiller
Germain Sommeiller was a civil engineer from Savoy. He directed the construction of the Fréjus Rail Tunnel between France and Italy, also known as the Mont Cenis Tunnel. This was the first of a series of major tunnels built in the late 19th century to connect northern and southern Europe through...

 (1815-1871) and his colleagues, Grandis and Grattoni, by 1861. Thereafter, many inventors refined the pneumatic drill.


The word "jackhammer" is used in North American English
North American English
North American English is the variety of the English language of North America, including that of the United States and Canada. Because of their shared histories and the similarities between the pronunciation, vocabulary and accent of American English and Canadian English, the two spoken languages...

 and Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, while "pneumatic drill" is used colloquially elsewhere in the English speaking world, although strictly speaking a "pneumatic drill" refers to a pneumatically driven jackhammer. In Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, the term "jackhammer" usually refers to electromechanical version of the tool.


A full-sized portable jackhammer is impractical for use against walls and steep slopes, except for a very strong man, as the user would have to both support the weight of the tool, and push the tool back against the work after each blow. A technique developed by experienced workmen is a two-man team to overcome this obstacle of gravity: one man operates the hammer and the second assists by holding the hammer either on his shoulders or cradled in his arms. Both use their combined weight to push the bit into the workface. This method is commonly referred to as horizontal jackhammering.

Another method is overhead jackhammering, requiring strength conditioning and endurance to hold a smaller jackhammer, called a rivet buster, over one's head. To make overhead work even safer a platform can be used. One such platform is a P.A.M. Positioner Actuator Manipulator. This unit take all the weight and vibration from the user.


A pneumatic jackhammer, also known as a or , is a jackhammer that uses compressed air as the power source. The air supply usually comes from a portable air compressor
Air compressor
An air compressor is a device that converts power into kinetic energy by compressing and pressurizing air, which, on command, can be released in quick bursts...

 driven by a diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

. Reciprocating compressor
Reciprocating compressor
A reciprocating compressor or piston compressor is a positive-displacement compressor that uses pistons driven by a crankshaft to deliver gases at high pressure....

s were formerly used. The unit comprised a reciprocating compressor driven, through a centrifugal clutch
Centrifugal clutch
A centrifugal clutch is a clutch that uses centrifugal force to connect two concentric shafts, with the driving shaft nested inside the driven shaft....

, by a diesel engine. The engine's governor
Governor (device)
A governor, or speed limiter, is a device used to measure and regulate the speed of a machine, such as an engine. A classic example is the centrifugal governor, also known as the Watt or fly-ball governor, which uses a rotating assembly of weights mounted on arms to determine how fast the engine...

 provided only two speeds:
  • idling, when the clutch was disengaged
  • maximum, when the clutch was engaged and the compressor was running

Modern versions use rotary compressors
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...

 and have more sophisticated variable governors. The unit is usually mounted on a trailer
Trailer (vehicle)
A trailer is generally an unpowered vehicle pulled by a powered vehicle. Commonly, the term trailer refers to such vehicles used for transport of goods and materials....

 and sometimes includes an electrical generator
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...

 to supply lights or electric power tools.

Additionally, some users of pneumatic jackhammers may use a pneumatic lubricator
Pneumatic lubricator
The pneumatic lubricator is a device which injects an aerosolized stream of oil into the airline. This is used to provide lubrication for internal working parts of pneumatic tools and components such as actuating cylinders, valves and motors....

 which is placed in series with the air hose powering the air hammer. This increases the life and performance of the jackhammer. Specific lubricant in filled in the pneumatic lubricator. Furthermore, air compressors typically incorporate moisture into the compressed air leading to freeze-ups of the jackhammer or air hammer in cold weather.


This tool is useful where the work is light and access to a compressor is limited or impractical. It requires a heavy duty extension cord to power the motor instead.


A hydraulic jackhammer, much larger than portable ones, may be fitted to mechanical excavator
Excavators are heavy construction equipment consisting of a boom, stick, bucket and cab on a rotating platform . The house sits atop an undercarriage with tracks or wheels. A cable-operated excavator uses winches and steel ropes to accomplish the movements. They are a natural progression from the...

s or backhoe
A backhoe, also called a rear actor or back actor, is a piece of excavating equipment or digger consisting of a digging bucket on the end of a two-part articulated arm. They are typically mounted on the back of a tractor or front loader...

s and is widely used for roadwork, quarrying and general demolition or construction groundwork. These larger machine mounted breakers are known as Rig Mounted, or Machine Mounted Breakers. Such tools can also be used against vertical walls (or ceilings for that matter), since the vehicles involved are massive enough and powerful enough to exert the forces involved without needing the help of gravity in operating the tool. Pneumatic or hydraulic tools are particularly likely to be used in mines
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...

 where there is an explosion risk (such as underground coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

 mines), since they lack any high-power electrical circuitry that might cause a triggering spark.

Hydraulic breakers
Breaker (hydraulic)
A breaker is a powerful percussion hammer fitted to an excavator for demolishing concrete structures or rocks. It is powered by an auxiliary hydraulic system from the excavator, which is fitted with a foot-operated valve for this purpose...

 usually use a hydraulic motor driving a sealed pneumatic hammer system, as a hydraulic hammer would develop a low strike speed and transfer unacceptable shock loads to the pump system.


Bit types include:
  • Spade - provides flat finish for concrete or edging in asphalt or dirt
  • Flat tip - allows direction control or finer edge finish
  • Point - general breaking
  • Stake driver - drives concrete form stakes
  • Scabbler - finishes surface smooth or for cleaning prior to bonding


The sound of the hammer blows, combined with the explosive air exhaust, makes pneumatic jackhammers dangerously loud, emitting 100 decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...

s at two meters. Sound-blocking earmuffs
Earmuffs are objects designed to cover a person's ears for protection. They consist of a thermoplastic or metal head-band, that fits over the top of the head, and a pad at each end, to cover the external ears....

 must be worn by the operator to prevent a form of hearing
Hearing (sense)
Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...

 damage of which tinnitus
Tinnitus |ringing]]") is the perception of sound within the human ear in the absence of corresponding external sound.Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period , ear...

 is the main symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

. Most pneumatic jackhammers now have a silencer around the barrel of the tool.

Prolonged exposure to the pronounced vibration
Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...

 set up by the tool can lead to blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

-circulation failures in the finger
A finger is a limb of the human body and a type of digit, an organ of manipulation and sensation found in the hands of humans and other primates....

s, a condition known as white finger. Applying athletic tape is not effective in preventing white finger but seems to help alleviate some of its discomfort. Pneumatic drill usage can also lead to a predisposition for development of carpal tunnel syndrome
Carpal tunnel syndrome
Carpal Tunnel Syndrome is an entrapment idiopathic median neuropathy, causing paresthesia, pain, and other symptoms in the distribution of the median nerve due to its compression at the wrist in the carpal tunnel. The pathophysiology is not completely understood but can be considered compression...


External links

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