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A hammer is a
tool
A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates ba ...
, most often a
hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive
nails into
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...
, to shape
metal
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...
(as with a
forge), or to crush
rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wales ...
.
Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include
carpentry,
blacksmithing,
warfare
War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regul ...
, and
percussive
A percussion instrument is a musical instrument that is sounded by being struck or scraped by a beater including attached or enclosed beaters or rattles struck, scraped or rubbed by hand or struck against another similar instrument. Exc ...
musicianship (as with a
gong
A gongFrom Indonesian and ms, gong; jv, ꦒꦺꦴꦁ ; zh, c=鑼, p=luó; ja, , dora; km, គង ; th, ฆ้อง ; vi, cồng chiêng; as, কাঁহ is a percussion instrument originating in East Asia and Southeast Asia. Gongs ...
).
Hammering is use of a hammer in its strike capacity, as opposed to
prying with a secondary claw or
grappling
Grappling, in hand-to-hand combat, describes sports that consist of gripping or seizing the opponent. Grappling is used at close range to gain a physical advantage over an opponent, either by imposing a position or causing injury. Grappling ...
with a secondary hook. Carpentry and blacksmithing hammers are generally wielded from a stationary stance against a stationary target as gripped and propelled with one
arm
In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...
, in a lengthy downward
planar
Planar is an adjective meaning "relating to a plane (geometry)".
Planar may also refer to:
Science and technology
* Planar (computer graphics), computer graphics pixel information from several bitplanes
* Planar (transmission line technologies), ...
arc—downward to add
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acc ...
to the impact—pivoting mainly around the shoulder and elbow, with a small but brisk wrist rotation shortly before impact; for extreme impact, concurrent motions of the torso and knee can lower the shoulder joint during the swing to further increase the length of the swing arc (but this is tiring). War hammers are often wielded in non-vertical planes of motion, with a far greater share of energy input provided from the legs and hips, which can also include a lunging motion, especially against moving targets. Small mallets can be swung from the wrists in a smaller motion permitting a much higher cadence of repeated strikes. Use of hammers and heavy mallets for
demolition must adapt the hammer stroke to the location and orientation of the target, which can necessitate a
clubbing or
golfing
Golf is a club-and-ball sport in which players use various clubs to hit balls into a series of holes on a course in as few strokes as possible.
Golf, unlike most ball games, cannot and does not use a standardized playing area, and coping w ...
motion with a two-handed grip.
The modern hammer head is typically made of
steel which has been
heat treated for hardness, and the handle (also known as a
haft or
helve) is typically made of wood or
plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...
.
Ubiquitous in
framing, the
claw hammer has a "claw" to pull nails out of wood, and is commonly found in an inventory of household tools in
North America. Other types of hammers vary in shape, size, and structure, depending on their purposes. Hammers used in many
trades include
sledgehammers,
mallets, and
ball-peen hammer
A ball-peen or ball pein hammer, also known as a machinist's hammer, is a type of peening hammer used in metalworking. It has two heads, one flat and the other, called the peen, rounded. It is distinguished from a cross-peen hammer, diagonal-peen ...
s. Although most hammers are hand tools,
powered hammers, such as
steam hammers and
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 ...
s, are used to deliver
forces beyond the capacity of the human arm. There are over 40 different types of hammers that have many different types of uses.
For hand hammers, the grip of the shaft is an important consideration. Many forms of hammering by hand are heavy work, and
perspiration
Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals.
Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distr ...
can lead to slippage from the hand, turning a hammer into a dangerous or destructive uncontrolled projectile. Steel is highly
elastic
Elastic is a word often used to describe or identify certain types of elastomer, elastic used in garments or stretchable fabrics.
Elastic may also refer to:
Alternative name
* Rubber band, ring-shaped band of rubber used to hold objects togeth ...
and transmits
shock
Shock may refer to:
Common uses Collective noun
*Shock, a historic commercial term for a group of 60, see English numerals#Special names
* Stook, or shock of grain, stacked sheaves
Healthcare
* Shock (circulatory), circulatory medical emergen ...
and
vibration
Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic, such as the motion of a pendulum—or random, su ...
; steel is also a good conductor of heat, making it unsuitable for contact with bare skin in frigid conditions. Modern hammers with steel shafts are almost invariably clad with a synthetic polymer to improve grip, dampen vibration, and to provide thermal insulation. A suitably contoured handle is also an important aid in providing a secure grip during heavy use. Traditional wooden handles were reasonably good in all regards, but lack strength and durability compared to steel, and there are safety issues with wooden handles if the head becomes loose on the shaft.
The high elasticity of the steel head is important in energy transfer, especially when used in conjunction with an equally elastic
anvil.
In terms of
human physiology
The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body.
It comprises a head ...
, many uses of the hammer involve coordinated
ballistic movement
Ballistic movement can be defined as muscle contractions that exhibit maximum velocities and accelerations over a very short period of time. They exhibit high firing rates, high force production, and very brief contraction times.
Physiology
Muscl ...
s under intense muscular forces which must be planned in advance at the
neuromuscular level, as they occur too rapidly for conscious adjustment in flight. For this reason, accurate striking at speed requires more practice than a tapping movement to the same target area. It has been suggested that the cognitive demands for pre-planning, sequencing and accurate timing associated with the related ballistic movements of
throwing
Throwing is an action which consists in accelerating a projectile and then releasing it so that it follows a ballistic trajectory, usually with the aim of impacting a remote target. This action is best characterized for animals with prehensile ...
, clubbing, and hammering precipitated aspects of
brain evolution in early
hominids.
History
The use of simple hammers dates to around 3.3 million years ago according to the 2012 find made by
Sonia Harmand
Sonia Harmand (born in 1974) is a French archaeologist who studies Early Stone Age archaeology and the evolution of stone tool making. She received her undergraduate degree from the University of Paris where she was associated with the "Prehistory ...
and Jason Lewis of
Stony Brook University, who while excavating a site near
Kenya
)
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, image_map =
, map_caption =
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, capital = Nairobi
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, largest_city = Nairobi
...
's
Lake Turkana discovered a very large deposit of various shaped stones including those used to strike
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...
,
bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...
, or other stones to break them apart and shape them.
The first hammers were made without handles. Stones attached to sticks with strips of
leather
Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffalo, pigs and hog ...
or
animal sinew were being used as hammers with handles by about 30,000 BCE during the middle of the
Paleolithic Stone Age. The addition of a handle gave the user better control and less accidents. The hammer became the primary tool used for building, food, and protection.
The hammer's archaeological record shows that it may be the oldest tool for which definite evidence exists.
File:StoneHammerDoverMN.JPG, A stone hammer found in Dover Township, Minnesota dated to 8000–3000 BCE, the North American Archaic period
File:Hammer stone tapping.jpg, Stone tapping hammer
File:Hammer stone head.jpg, Perforated hammer head of stone
File:Sacrificial hammer Dodona Louvre Br1183 n2.jpg, Ancient Greek bronze sacrificial hammer, 7th century BCE, from Dodona
Dodona (; Doric Greek: Δωδώνα, ''Dōdṓnā'', Ionic and Attic Greek: Δωδώνη, ''Dōdṓnē'') in Epirus in northwestern Greece was the oldest Hellenic oracle, possibly dating to the second millennium BCE according to Herodotus. Th ...
File:Melencolia I (Durero) hammer crop.jpg, 16th-century claw hammer; detail from Dürer's ''Melencolia I
''Melencolia I'' is a large 1514 engraving by the German Renaissance artist Albrecht Dürer. The print's central subject is an enigmatic and gloomy winged female figure thought to be a personification of melancholia – melancholy. Holding her h ...
'' (c. 1514)
Construction and materials
A traditional hand-held hammer consists of a separate head and a handle, which can be fastened together by means of a special
wedge
A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converti ...
made for the purpose, or by
glue, or both. This two-piece design is often used to combine a dense metallic striking head with a non-metallic mechanical-shock-absorbing handle (to reduce
user fatigue from repeated strikes). If wood is used for the handle, it is often
hickory or
ash
Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
, which are tough and long-lasting materials that can dissipate
shock wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...
s from the hammer head.
Rigid
fiberglass resin may be used for the handle; this material does not absorb water or decay but does not dissipate shock as well as wood.
A loose hammer head is considered hazardous due to the risk of the head becoming detached from the handle while being swung becoming a dangerous uncontrolled projectile. Wooden handles can often be replaced when worn or damaged; specialized kits are available covering a range of handle sizes and designs, plus special wedges and spacers for secure attachment.
Some hammers are one-piece designs made mostly of a single material. A one-piece metallic hammer may optionally have its handle coated or wrapped in a
resilient
Resilience, resilient, resiliency, or ''variation'', may refer to:
Science
Ecology
* Ecological resilience, the capacity of an ecosystem to recover from perturbations
** Climate resilience, the ability of systems to recover from climate change
* ...
material such as
rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, an ...
for improved grip and to reduce user fatigue.
The hammer head may be surfaced with a variety of materials including
brass
Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other wit ...
,
bronze, wood, plastic, rubber, or leather. Some hammers have interchangeable striking surfaces, which can be selected as needed or replaced when worn out.
Designs and variations
![Peen hammers](https://upload.wikimedia.org/wikipedia/commons/7/75/Peen_hammers.png)
A large hammer-like tool is a ''maul'' (sometimes called a "beetle"), a wood- or rubber-headed hammer is a ''
mallet'', and a hammer-like tool with a cutting blade is usually called a ''
hatchet
A hatchet (from the Old French , a diminutive form of ''hache'', ' axe' of Germanic origin) is a single-handed striking tool with a sharp blade on one side used to cut and split wood, and a hammerhead on the other side. Hatchets may also be us ...
''. The essential part of a hammer is the head, a compact solid mass that is able to deliver a blow to the intended target without itself deforming. The impacting surface of the tool is usually flat or slightly rounded; the opposite end of the impacting mass may have a ball shape, as in the
ball-peen hammer
A ball-peen or ball pein hammer, also known as a machinist's hammer, is a type of peening hammer used in metalworking. It has two heads, one flat and the other, called the peen, rounded. It is distinguished from a cross-peen hammer, diagonal-peen ...
. Some
upholstery hammer
An upholstery hammer (also called a tack hammer) is a lightweight hammer used for securing upholstery fabric to furniture upholstery frame, frames using Thumbtack, tacks or small nails.
Many styles have two faces, one face usually being magneti ...
s have a
magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nicke ...
ized face, to pick up tacks. In the hatchet, the flat hammer head may be secondary to the cutting edge of the tool.
The impact between steel hammer heads and the objects being hit can create
sparks, which may ignite
flammable or
explosive gas
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...
es. These are a
hazard in some industries such as
underground coal mining (due to the presence of
methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...
gas), or in other hazardous environments such as
petroleum refineries
An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into useful products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liquefie ...
and
chemical plants. In these environments, a variety of non-sparking metal tools are used, primarily made of
aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
or
beryllium copper. In recent years, the handles have been made of durable plastic or rubber, though wood is still widely used because of its shock-absorbing qualities and repairability.
Hand-powered
*
Ball-peen hammer
A ball-peen or ball pein hammer, also known as a machinist's hammer, is a type of peening hammer used in metalworking. It has two heads, one flat and the other, called the peen, rounded. It is distinguished from a cross-peen hammer, diagonal-peen ...
,
[''British Standard BS 876:1995 Specification for Hand Hammers''] or mechanic's hammer
* Boiler scaling hammer
* Brass hammer, also known as non-sparking hammer or spark-proof hammer and used mainly in flammable areas like oil fields
* Bricklayer's hammer
* Carpenter's hammer (used for nailing), such as the
framing hammer
A framing hammer is a form of claw hammer used for heavy wood construction, particularly house framing and concrete formwork. It is a heavy duty with a straight claw and a wood, metal, or fiberglass handle. Head weights vary from 20 to 32 ...
and the
claw hammer, and pinhammers (ball-peen and cross-peen types)
* Cow hammer – sometimes used for
livestock slaughter, a practice now
deprecated
In several fields, especially computing, deprecation is the discouragement of use of some terminology, feature, design, or practice, typically because it has been superseded or is no longer considered efficient or safe, without completely removing ...
due to
animal welfare objections
* Cross-peen hammer,
having one round face and one wedge-peen face.
*
Dead blow hammer
A dead-blow hammer is a specialized mallet helpful in minimizing damage to the struck surface and in controlling striking force, with minimal rebound from the struck surface. The minimal rebound is helpful in avoiding accidental damage to preci ...
delivers impact with very little recoil, often due to a hollow head filled with sand,
lead shot
Shot is a collective term for small spheres or pellets, often made of lead. These were the original projectiles for shotguns and are still fired primarily from shotguns and less commonly from riot guns and grenade launchers, although shot shell ...
or pellets
* Demolition hammer
*
Drilling hammer – a short handled sledgehammer originally used for drilling in rock with a chisel. The name usually refers to a hammer with a head and a handle, also called a "single-jack" hammer because it was used by one person drilling, holding the chisel in one hand and the hammer in the other. In modern usage, the term is mostly interchangeable with "engineer's hammer", although it can indicate a version with a slightly shorter handle.
* Engineer's hammer, a short-handled hammer, was originally an essential components of a
railroad engineer
A train driver, engine driver, engineman or locomotive driver, commonly known as an engineer or railroad engineer in the United States and Canada, and also as a locomotive handler, locomotive operator, train operator, or motorman, is a pers ...
's toolkit for working on steam locomotives. Typical weight is 2–4 lbs (0.9–1.8 kg) with a 12–14-inch (30–35 cm) handle. Originally these were often cross-peen hammers, with one round face and one wedge-peen face, but in modern usage the term primarily refers to hammers with two round faces.
*
Gavel
A gavel is a small ceremonial mallet commonly made of hardwood, typically fashioned with a handle. It can be used to call for attention or to punctuate rulings and proclamations and is a symbol of the authority and right to act officially in the ...
, used by judges and presiding authorities to draw attention
*
Geologist's hammer
A geologist's hammer, rock hammer, rock pick, geological pick, or informally geo pick, is a hammer used for splitting and breaking rocks. In field geology, they are used to obtain a fresh surface of a rock to determine its composition, bedding or ...
or rock pick
* Joiner's hammer, or
Warrington hammer
The Warrington hammer is a common woodworking tool that falls under the cross-peen category of hammers. The chisel-like cross-peen side of the hammer is used to set small nails and pins while the smaller, rounded face is used to finish driving in t ...
* Knife-edged hammer, its properties developed to aid a hammerer in the act of slicing whilst bludgeoning
*
Lathe hammer (also known as a lath hammer, lathing hammer, or lathing hatchet), a tool used for cutting and nailing wood
lath
A lath or slat is a thin, narrow strip of straight-wood grain, grained wood used under roof shingles or tiles, on lath and plaster walls and ceilings to hold plaster, and in Latticework, lattice and Trellis (architecture), trellis work.
''Lath ...
, which has a small hatchet blade on one side (with a small, lateral nick for pulling nails) and a hammer head on the other
*
Lump hammer
A sledgehammer is a tool with a large, flat, often metal head, attached to a long handle. The long handle combined with a heavy head allows the sledgehammer to gather momentum during a swing and apply a large force compared to hammers designed t ...
, or club hammer
*
Mallets, including versions made with hard rubber or rolled sheets of
rawhide
* Railway track keying hammer
* Magnetic double-head hammer
* Magnetic tack hammer
*
Rock climbing hammer
Rock climbing hammers, also known as wall hammers, big wall hammers, or aid hammers, are a type of specialty hammer used mainly in aid climbing for the placement and removal of pitons, copper-heads, and circle-heads. They can also be used in th ...
* Rounding hammer, Blacksmith or farrier hammer. Round face generally for moving or drawing metal and flat for "planishing" or smoothing out the surface marks.
* Shingler's hammer
*
Sledgehammer
*
Soft-faced hammer
*
Spiking hammer
*
Splitting maul
A splitting maul also known as a ''block buster'', ''block splitter'', ''chop and maul'', ''sledge axe'', ''go-devil'' or ''hamaxe'' is a heavy, long-handled axe used for splitting a piece of wood along its grain. One side of its head is like a ...
* Strike Tack hammer
*
Stonemason's hammer
*
Tinner's hammer
*
Upholstery hammer
An upholstery hammer (also called a tack hammer) is a lightweight hammer used for securing upholstery fabric to furniture upholstery frame, frames using Thumbtack, tacks or small nails.
Many styles have two faces, one face usually being magneti ...
*
Welder's chipping hammer
Mechanically powered
![Boxholms bruksmuseum, den 18 oktober 2008, bild 38](https://upload.wikimedia.org/wikipedia/commons/7/7f/Boxholms_bruksmuseum%2C_den_18_oktober_2008%2C_bild_38.JPG)
Mechanically powered hammers often look quite different from the hand tools, but nevertheless, most of them work on the same principle. They include:
*
Hammer drill
A hammer drill, also known as a percussion drill or impact drill, is a power tool used chiefly for drilling in hard materials. It is a type of rotary drill with an impact mechanism that generates a hammering motion. The percussive mechanism prov ...
, that combines a jackhammer-like mechanism with a
drill
*
High Frequency Impact Treatment
The high-frequency impact treatment or HiFIT – Method is the treatment of welded steel constructions at the weld transition to increase the fatigue strength.
Features
The durability and life of dynamically loaded, welded steel structures is ...
hammer – for after-treatment of weld transitions
*
Jackhammer
A jackhammer (pneumatic drill or demolition hammer in British English) is a pneumatic or electro-mechanical tool that combines a hammer directly with a chisel. It was invented by William Mcreavy, who then sold the patent to Charles Brady King ...
*
Steam hammer
*
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 ...
*
Nail gun
A nail gun, nailgun or nailer is a form of hammer used to drive nails into wood or other materials. It is usually driven by compressed air (pneumatic), electromagnetism, highly flammable gases such as butane or propane, or, for powder-actuate ...
*
Staple gun
A staple gun or powered stapler is a hand-held machine used to drive heavy metal staples into wood, plastic, or masonry. Staple guns are used for many different applications and to affix a variety of materials, including insulation, house wrap ...
Associated tools
*
Anvil
*
Chisel
*
Pipe drift (Blacksmithing – spreading a punched hole to proper size and/or shape)
*
Star drill
*
Punch
Punch commonly refers to:
* Punch (combat), a strike made using the hand closed into a fist
* Punch (drink), a wide assortment of drinks, non-alcoholic or alcoholic, generally containing fruit or fruit juice
Punch may also refer to:
Places
* Pun ...
*
Woodsplitting maul – can be hit with a sledgehammer for splitting wood.
*
Woodsplitting wedge – hit with a sledgehammer for splitting wood.
Physics
As a force amplifier
A hammer is a simple
force amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost t ...
that works by converting
mechanical work
In physics, work is the energy transferred to or from an object via the application of force along a displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the product of the force stre ...
into
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acc ...
and back.
In the swing that precedes each blow, the hammer head stores a certain amount of kinetic energy—equal to the length ''D'' of the swing times the force ''f'' produced by the
muscles of the arm and by
gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
. When the hammer strikes, the head is stopped by an opposite force coming from the target, equal and opposite to the force applied by the head to the target. If the target is a hard and heavy object, or if it is resting on some sort of
anvil, the head can travel only a very short distance ''d'' before stopping. Since the stopping force ''F'' times that distance must be equal to the head's kinetic energy, it follows that ''F'' is much greater than the original driving force ''f''—roughly, by a factor ''D''/''d''. In this way, great strength is not needed to produce a force strong enough to bend steel, or crack the hardest stone.
Effect of the head's mass
The amount of energy delivered to the target by the hammer-blow is equivalent to one half the mass of the head times the square of the head's speed at the time of impact
. While the energy delivered to the target increases linearly with mass, it increases quadratically with the
speed
In everyday use and in kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (ma ...
(see the effect of the handle, below). High tech
titanium
Titanium is a chemical element with the Symbol (chemistry), symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resista ...
heads are lighter and allow for longer handles, thus increasing velocity and delivering the same energy with less arm fatigue than that of a heavier steel head hammer.
A titanium head has about 3%
recoil
Recoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force r ...
energy and can result in greater efficiency and less fatigue when compared to a steel head with up to 30% recoil.
Dead blow hammer
A dead-blow hammer is a specialized mallet helpful in minimizing damage to the struck surface and in controlling striking force, with minimal rebound from the struck surface. The minimal rebound is helpful in avoiding accidental damage to preci ...
s use special rubber or steel shot to absorb
recoil
Recoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force r ...
energy, rather than bouncing the hammer head after impact.
Effect of the handle
The handle of the hammer helps in several ways. It keeps the user's hands away from the point of impact. It provides a broad area that is better-suited for gripping by the hand. Most importantly, it allows the user to maximize the speed of the head on each blow. The primary constraint on additional handle length is the lack of space to swing the hammer. This is why sledgehammers, largely used in open spaces, can have handles that are much longer than a standard carpenter's hammer. The second most important constraint is more subtle. Even without considering the effects of fatigue, the longer the handle, the harder it is to guide the head of the hammer to its target at full speed.
Most designs are a compromise between practicality and energy efficiency. With too long a handle, the hammer is inefficient because it delivers force to the wrong place, off-target. With too short a handle, the hammer is inefficient because it doesn't deliver enough force, requiring more blows to complete a given task. Modifications have also been made with respect to the effect of the hammer on the user. Handles made of shock-absorbing materials or varying angles attempt to make it easier for the user to continue to wield this age-old device, even as nail guns and other powered drivers encroach on its traditional field of use.
As hammers must be used in many circumstances, where the position of the person using them cannot be taken for granted, trade-offs are made for the sake of practicality. In areas where one has plenty of room, a long handle with a heavy head (like a sledgehammer) can deliver the maximum amount of energy to the target. It is not practical to use such a large hammer for all tasks, however, and thus the overall design has been modified repeatedly to achieve the optimum utility in a wide variety of situations.
Effect of gravity
Gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
exerts a force on the hammer head. If hammering downwards, gravity increases the
acceleration
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by t ...
during the hammer stroke and increases the
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...
delivered with each blow. If hammering upwards, gravity reduces the acceleration during the hammer stroke and therefore reduces the energy delivered with each blow. Some hammering methods, such as traditional mechanical
pile drivers, rely entirely on gravity for acceleration on the down stroke.
Ergonomics and injury risks
A hammer may cause significant injury if it strikes the body. Both manual and powered hammers can cause
peripheral neuropathy
Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or or ...
or a variety of other ailments when used improperly. Awkward handles can cause
repetitive stress injury
A repetitive strain injury (RSI) is an injury to part of the musculoskeletal or nervous system caused by repetitive use, vibrations, compression or long periods in a fixed position. Other common names include repetitive stress disorders, cumula ...
(RSI) to hand and arm joints, and uncontrolled shock waves from repeated impacts can injure nerves and the skeleton. Additionally, striking metal objects with a hammer may produce small metallic projectiles which can become lodged in the eye. It is therefore recommended to wear
safety glasses
Glasses, also known as eyeglasses or spectacles, are vision eyewear, with lenses (clear or tinted) mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms (known as temples or ...
.
War hammers
A war hammer is a
late medieval
The Late Middle Ages or Late Medieval Period was the period of European history lasting from AD 1300 to 1500. The Late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period (and in much of Europe, the Renai ...
weapon
A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, ...
of
war
War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regular o ...
intended for
close combat
Close combat means a violent physical confrontation between two or more opponents at short range.''MCRP 3-02B: Close Combat'', Washington, D.C.: Department Of The Navy, Headquarters United States Marine Corps, 12 February 1999Matthews, Phil, CQB ...
action.
Symbolism
![Tampere](https://upload.wikimedia.org/wikipedia/commons/9/9f/Tampere.vaakuna.svg)
The hammer, being one of the most used tools by
man
A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromo ...
, has been used very much in symbols such as
flags and
heraldry. In the Middle Ages, it was used often in blacksmith guild logos, as well as in many family symbols. The
hammer and pick
The hammer and pick, rarely referred to as hammer and chisel, is a symbol of mining, often used in heraldry. It can indicate mining, mines (especially on maps or in cartography), or miners, and is also borne as a charge in the coats of arms o ...
are used as a symbol of mining.
In mythology, the gods
Thor
Thor (; from non, Þórr ) is a prominent god in Germanic paganism. In Norse mythology, he is a hammer-wielding god associated with lightning, thunder, storms, sacred groves and trees, strength, the protection of humankind, hallowing, an ...
(
Norse) and
Sucellus (
Celtic
Celtic, Celtics or Keltic may refer to:
Language and ethnicity
*pertaining to Celts, a collection of Indo-European peoples in Europe and Anatolia
**Celts (modern)
*Celtic languages
**Proto-Celtic language
* Celtic music
*Celtic nations
Sports Fo ...
and
Gallo-Roman
Gallo-Roman culture was a consequence of the Romanization of Gauls under the rule of the Roman Empire. It was characterized by the Gaulish adoption or adaptation of Roman culture, language, morals and way of life in a uniquely Gaulish context ...
), and the hero
Hercules
Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures.
The Romans adapted the ...
(
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
), all had hammers that appear in their lore and carried different meanings. Thor, the god of thunder and lightning, wields a hammer named
Mjölnir
Mjölnir (from Old Norse Mjǫllnir) is the hammer of the thunder god Thor in Norse mythology, used both as a devastating weapon and as a divine instrument to provide blessings. The hammer is attested in numerous sources, including the 11th cen ...
. Many artifacts of decorative hammers have been found, leading modern practitioners of this religion to often wear reproductions as a sign of their faith.
In
American folklore
American folklore encompasses the folklores that have evolved in the present-day United States since Europeans arrived in the 16th century. While it contains much in the way of Native American tradition, it is not wholly identical to the tribal ...
, the hammer of
John Henry represents the strength and endurance of a man.
A political party in Singapore,
Workers' Party of Singapore
The Workers' Party (abbreviation: WP) is a major centre-left political party in Singapore and is one of the three contemporary political parties represented in Parliament, alongside the governing People's Action Party (PAP) and opposition Progr ...
, based their logo on a hammer to symbolize the party's
civic nationalism and
social democracy
Social democracy is a political, social, and economic philosophy within socialism that supports political and economic democracy. As a policy regime, it is described by academics as advocating economic and social interventions to promote s ...
ideology.
A variant, well-known symbol with a hammer in it is the
Hammer and Sickle, which was the symbol of the former
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
and is strongly linked to
communism
Communism (from Latin la, communis, lit=common, universal, label=none) is a far-left sociopolitical, philosophical, and economic ideology and current within the socialist movement whose goal is the establishment of a communist society, a ...
and early
socialism
Socialism is a left-wing Economic ideology, economic philosophy and Political movement, movement encompassing a range of economic systems characterized by the dominance of social ownership of the means of production as opposed to Private prop ...
. The hammer in this symbol represents the industrial working class (and the sickle represents the agricultural working class). The hammer is used in some coats of arms in former socialist countries like
East Germany
East Germany, officially the German Democratic Republic (GDR; german: Deutsche Demokratische Republik, , DDR, ), was a country that existed from its creation on 7 October 1949 until its dissolution on 3 October 1990. In these years the state ...
. Similarly, the Hammer and Sword symbolizes
Strasserism
Strasserism (german: Strasserismus or ''Straßerismus'') is a strand of Nazism calling for a more radical, mass-action and worker-based form of the ideology, espousing economic antisemitism above other antisemitic forms, to achieve a national ...
, a strand of
National Socialism
Nazism ( ; german: Nazismus), the common name in English for National Socialism (german: Nationalsozialismus, ), is the far-right totalitarian political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in Naz ...
seeking to appeal to the working class. Another variant of the symbol was used for the North Korean party,
Workers' Party of Korea
The Workers' Party of Korea (WPK) is the founding and sole ruling party of the Democratic People's Republic of Korea, commonly known as North Korea. Founded in 1949 from the merger of the Workers' Party of North Korea and the Workers' Party ...
, incorporated with an
ink brush
Ink is a gel, sol, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface to produce an image, text, or design. Ink is used for drawing or writing with a pen, brush, reed pen, or quill. ...
on the middle, which symbolizes both
Juche
''Juche'' ( ; ), officially the ''Juche'' idea (), is the state ideology of North Korea and the official ideology of the Workers' Party of Korea. North Korean sources attribute its conceptualization to Kim Il-sung, the country's founder and f ...
and
Songun
''Songun'' is the " military-first" policy of North Korea, prioritizing the Korean People's Army in the affairs of state and allocation of resources. "Military-first" as a principle guides political and economic life in North Korea, with "mili ...
ideologies.
In
Pink Floyd – The Wall
''Pink Floyd – The Wall'' is a 1982 British live-action/animated psychological musical drama film directed by Alan Parker, based on Pink Floyd's 1979 album of the same name. The screenplay was written by Pink Floyd vocalist and bassist Rog ...
, two hammers crossed are used as a symbol for the fascist takeover of the concert during "
In the Flesh In the Flesh may refer to:
Books
* ''In the Flesh'' (2009 graphic novel), a collection of stories by Koren Shadmi
Film and TV
* ''In the Flesh'' (1998 film), an American gay-themed murder mystery film
* ''In the Flesh'' (2003 film), an Indian ...
". This also has the meaning of the hammer beating down any "nails" that stick out.
The
gavel
A gavel is a small ceremonial mallet commonly made of hardwood, typically fashioned with a handle. It can be used to call for attention or to punctuate rulings and proclamations and is a symbol of the authority and right to act officially in the ...
, a small wooden mallet, is used to symbolize a mandate to preside over a meeting or judicial proceeding, and a graphic image of one is used as a symbol of legislative or judicial decision-making authority.
Judah Maccabee
Judah Maccabee (or Judas Maccabeus, also spelled Machabeus, or Maccabæus, Hebrew: יהודה המכבי, ''Yehudah HaMakabi'') was a Jewish priest (''kohen'') and a son of the priest Mattathias. He led the Maccabean Revolt against the Seleu ...
was nicknamed "The Hammer", possibly in recognition of his ferocity in battle. The name "Maccabee" may derive from the
Aramaic
The Aramaic languages, short Aramaic ( syc, ܐܪܡܝܐ, Arāmāyā; oar, 𐤀𐤓𐤌𐤉𐤀; arc, 𐡀𐡓𐡌𐡉𐡀; tmr, אֲרָמִית), are a language family containing many varieties (languages and dialects) that originated in ...
''maqqaba''. (see .)
The hammer in the song "
If I Had a Hammer
"If I Had a Hammer (The Hammer Song)" is a protest song written by Pete Seeger and Lee Hays. It was written in 1949 in support of the Progressive movement, and was first recorded by the Weavers, a folk music quartet composed of Seeger, Hays, ...
" represents a relentless message of justice broadcast across the land. The song became a symbol of the
civil rights movement
The civil rights movement was a nonviolent social and political movement and campaign from 1954 to 1968 in the United States to abolish legalized institutional racial segregation, discrimination, and disenfranchisement throughout the Unite ...
.
Image gallery
File:Buck Knives Hammer (5075278861).jpg, Ball-peen hammer
A ball-peen or ball pein hammer, also known as a machinist's hammer, is a type of peening hammer used in metalworking. It has two heads, one flat and the other, called the peen, rounded. It is distinguished from a cross-peen hammer, diagonal-peen ...
File:Stockhammer.JPG, Bush hammer
A bush hammer, also known as an axe hammer, is a masonry tool used to texturize stone and concrete. The term is derived from the German word ''bosshammer'', where Old German ''bossen'' meant "to beat".
Description and use
Bush hammers exist in ...
File:Hammer2.jpg, Claw hammer
File:Hammer-1.jpg, Cross-peen hammer
File:Hammer dog-head.jpg, Dog-head hammer (blacksmithing)
File:Framing hammer.jpg, Framing hammer
A framing hammer is a form of claw hammer used for heavy wood construction, particularly house framing and concrete formwork. It is a heavy duty with a straight claw and a wood, metal, or fiberglass handle. Head weights vary from 20 to 32 ...
File:BrokenConcretion22.jpg, Geologist's hammer
A geologist's hammer, rock hammer, rock pick, geological pick, or informally geo pick, is a hammer used for splitting and breaking rocks. In field geology, they are used to obtain a fresh surface of a rock to determine its composition, bedding or ...
File:Hifit-hammer.jpg, HiFIT-hammer for aftertreatment of weld transitions
File:Hammer Long cross-face.jpg, Long cross-face hammer (blacksmithing)
File:Sledgehammer.jpg, Post maul
File:Climbing Hammer.png, Rock climbing hammer
Rock climbing hammers, also known as wall hammers, big wall hammers, or aid hammers, are a type of specialty hammer used mainly in aid climbing for the placement and removal of pitons, copper-heads, and circle-heads. They can also be used in th ...
File:Gummihammer.png, Rubber mallet
File:Sledgehammers-1.jpg, Sledgehammers
File:Hammer straight pane sledge.jpg, Straight pane sledgehammer
File:Hammer twist.jpg, Twist hammer (blacksmithing)
File:Hammer tapissier.jpg, Upholstery hammer
An upholstery hammer (also called a tack hammer) is a lightweight hammer used for securing upholstery fabric to furniture upholstery frame, frames using Thumbtack, tacks or small nails.
Many styles have two faces, one face usually being magneti ...
File:Mallet menuisier.jpg, Wooden mallet
See also
*
Hammer Museum (Haines, Alaska)
*
Mjölnir
Mjölnir (from Old Norse Mjǫllnir) is the hammer of the thunder god Thor in Norse mythology, used both as a devastating weapon and as a divine instrument to provide blessings. The hammer is attested in numerous sources, including the 11th cen ...
References
External links
Types of Hammers(images and descriptions)
"Choosing a Hammer".''Popular Science'', June 1960, pp. 164–167.
{{Authority control
*
Woodworking hand tools
Metalworking tools