AskDefine | Define hammer

Dictionary Definition

hammer

Noun

1 the part of a gunlock that strikes the percussion cap when the trigger is pulled [syn: cock]
2 a hand tool with a heavy rigid head and a handle; used to deliver an impulsive force by striking
3 an athletic competition in which a heavy metal ball that is attached to a flexible wire is hurled as far as possible [syn: hammer throw]
4 the ossicle attached to the eardrum [syn: malleus]
5 a heavy metal sphere attached to a flexible wire; used in the hammer throw
6 a striker that is covered in felt and that causes the piano strings to vibrate
7 a power tool for drilling rocks [syn: power hammer]
8 the act of pounding (delivering repeated heavy blows); "the sudden hammer of fists caught him off guard"; "the pounding of feet on the hallway" [syn: pound, hammering, pounding]

Verb

1 beat with or as if with a hammer; "hammer the metal flat"
2 create by hammering; "hammer the silver into a bowl"; "forge a pair of tongues" [syn: forge]

User Contributed Dictionary

see Hammer

English

Etymology

Old English hamor < Germanic *hamara-. Cognate with Dutch hamer, German Hammer, Swedish hammare.

Pronunciation

  • /ˈhæmə/, /"h

Extensive Definition

A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. Usual features are a handle and a head, with most of the weight in the head. The basic design is hand-operated, but there are also many mechanically operated models for heavier uses.
The hammer is a basic tool of many professions, and can also be used as a weapon. By analogy, the name hammer has also been used for devices that are designed to deliver blows, e.g. in the caplock mechanism of firearms.

History

The use of simple tools dates to about 2,400,000 BCE when various shaped stones were used to strike wood, bone, or other stones to and break them apart and shape them. Stones attached to sticks with strips of leather or animal sinew were being used as hammers by about 30,000 BCE during the middle of the Paleolithic Stone Age. Its archeological record means it is perhaps the oldest human tool known.

Designs and variations

The essential part of a hammer is the head, a compact solid mass that is able to deliver the blow to the intended target without itself deforming.
The opposite side of a ball as in the ball-peen hammer and the cow hammer. Some upholstery hammers have a magnetized appendage, to pick up tacks. In the hatchet the hammer head is secondary to the cutting edge of the tool.
In recent years the handles have been made of durable plastic or rubber. The hammer varies at the top, some are larger than others giving a larger surface area to hit different sized nails and such,
Popular hand-powered variations include:
image:hammer2.jpg|Claw hammer image:Hammer stone tapping.jpg|Stone tapping hammer
Mechanically-powered hammers often look quite different from the hand tools, but nevertheless most of them work on the same principle. They include:
In professional framing carpentry, the hammer has almost been completely replaced by the nail gun. In professional upholstery, its chief competitor is the staple gun.

Tools used in conjunction with hammers

The physics of hammering

Hammer as a force amplifier

A hammer is basically a force amplifier that works by converting mechanical work into kinetic energy and back.
In the swing that precedes each blow, a certain amount of kinetic energy gets stored in the hammer's head, equal to the length D of the swing times the force f produced by the muscles of the arm and by gravity. When the hammer strikes, the head gets stopped by an opposite force coming from the target; which is 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 will be 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 (E=). While the energy delivered to the target increases linearly with mass, it increases geometrically with the speed (see the effect of the handle, below). High tech titanium heads are lighter and allow for longer handles, thus increasing velocity and delivering more energy with less arm fatigue than that of a steel head hammer of the same weight. 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 sledge hammer) can deliver the maximum amount of energy to the target. But clearly, it's unreasonable to use a sledge hammer to drive upholstery tacks. Thus, the overall design has been modified repeatedly to achieve the optimum utility in a wide variety of situations.

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 in which to swing the hammer. This is why sledge hammers, 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. Too long a handle: the hammer is inefficient because it delivers force to the wrong place, off-target. Too short a handle: the hammer is inefficient because it doesn't deliver enough force, requiring more blows to complete a given task. Recently, modifications have also been made with respect to the effect of the hammer on the user. A titanium head has about 3% recoil and can result in greater efficiency and less fatigue when compared to a steel head with about 27% recoil. 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.

War hammers

The concept of putting a handle on a weight to make it more convenient to use may well have led to the very first weapons ever invented. The club is basically a variant of a hammer. In the Middle Ages, the war hammer became popular when edged weapons could no longer easily penetrate some forms of armour.

Symbolic hammers

The hammer is associated with West Ham United, who are nicknamed 'The Hammers' and have a symbol of two crossed hammers on the team crest. The origin of this goes back to the club's beginning in the 19th Century, when the Thames Ironworks company football team turned professional in 1895, and became renamed as West Ham United. Two hammers crossed is a mining symbol.
The hammer, being one of the most used tools by Homo sapiens, has been used very much in symbols and arms. In the Middle Ages it was used often in blacksmith guild logos, as well as in many family symbols. The most recognised symbol with a hammer in it is the Hammer and Sickle, which was the symbol of the former Soviet Union. The hammer in this symbol represents the industrial working class (and the sickle the agricultural working class). The hammer is used in some coat of arms in (former) socialist (or pseudo socialist) countries like East Germany.
In Norse Mythology, Thor, the god of thunder and lightning, wields a hammer named Mjolnir. Many artifacts of decorative hammers have been found leading many modern practitioners of this religion to often wear reproductions as a sign of their faith.
"The Hammer" is also the nickname of David Thoresen, a fight club member, who is also known as "Thor".
In the 1982 film Pink Floyd The Wall, a circular logo featuring two crossed hammers was used on armbands, flags, and banners during the fascist rally scene. These hammers were also featured in the famous "marching hammers" animation loop and the video for "Another Brick in the Wall (Part II)".
The Beatles song "Maxwell's Silver Hammer" is about a fictional serial killer named Maxwell Edison whose murder weapon is a silver hammer.
MC Hammer's 1990 hit "U Can't Touch This" popularised the term "Hammer Time" as a cue for dancing.
The song If I Had a Hammer has been a top ten hit and was considered an anthem of the Civil Rights Movement. It has been recorded by many artists, including Peter, Paul, and Mary, Trini Lopez, and Leonard Nimoy. The song begins:
If I had a hammer I'd hammer in the morning
I'd hammer in the evening all over this land
I'd hammer out danger, I'd hammer out warning
I'd hammer out love between my brothers and my sisters
All over this land
In ultimate frisbee, the hammer is a commonly used overhead throw that is thrown vertically and turns over to land upside down horizontally.

External links

hammer in Old English (ca. 450-1100): Hamor
hammer in Arabic: مطرقة
hammer in Bosnian: Čekić
hammer in Bulgarian: Чук
hammer in Catalan: Martell
hammer in Czech: Kladivo
hammer in Danish: Hammer
hammer in German: Hammer
hammer in Estonian: Vasar
hammer in Modern Greek (1453-): Σφυρί
hammer in Spanish: Martillo
hammer in Esperanto: Martelo
hammer in Persian: چکش
hammer in French: Marteau (outil)
hammer in Gilaki: چکوش
hammer in Korean: 망치
hammer in Hindi: हथौड़ा
hammer in Croatian: Čekić
hammer in Ido: Martelo
hammer in Icelandic: Hamar
hammer in Italian: Martello (tecnologia)
hammer in Hebrew: פטיש
hammer in Pampanga: Martiliu
hammer in Latin: Malleus (instrumentum)
hammer in Luxembourgish: Hummer (Handwierksgeschir)
hammer in Lithuanian: Plaktukas
hammer in Dutch: Hamer (gereedschap)
hammer in Japanese: 槌
hammer in Norwegian: Hammer (redskap)
hammer in Norwegian Nynorsk: Hammar
hammer in Narom: Marté
hammer in Polish: Młotek
hammer in Portuguese: Martelo
hammer in Quechua: Takana
hammer in Russian: Молоток
hammer in Sicilian: Marteddu
hammer in Simple English: Hammer
hammer in Slovak: Kladivo (nástroj)
hammer in Serbian: Чекић
hammer in Finnish: Vasara
hammer in Swedish: Hammare (handverktyg)
hammer in Tamil: சுத்தியல்
hammer in Thai: ค้อน
hammer in Turkish: Çekiç
hammer in Vlaams: Oamer
hammer in Yiddish: האמער
hammer in Samogitian: Kūjātis
hammer in Chinese: 鎚

Synonyms, Antonyms and Related Words

Eustachian tube, air hammer, anvil, assault, attack, auditory apparatus, auditory canal, auditory meatus, auditory nerve, auditory ossicles, auditory tube, auricle, ball peen hammer, bang, barbarize, basilar membrane, baste, batter, beat, beetle, belabor, bony labyrinth, brutalize, buffet, burn, butcher, carry on, cauliflower ear, chipping hammer, claw hammer, cochlea, conch, concha, destroy, dig, din, ding, drive, drop hammer, drub, drudge, drum, drumhead, ear, ear lobe, eardrum, elaborate, electric hammer, endolymph, external ear, fag, fashion, flail, flap, form, go on, grave, grind, grub, hammer away, incus, inner ear, jackhammer, knock, lambaste, larrup, lay waste, lobe, lobule, loot, lug, mallet, malleus, mastoid process, maul, middle ear, moil, mug, organ of Corti, outer ear, oval window, paste, patter, peg, peg away, pelt, perilymph, pile hammer, pillage, pinna, plod, plug, plug along, plug away, pommel, pound, pound away, pulverize, pummel, rage, raising hammer, ramp, rampage, rant, rap, rape, rave, riot, riveting hammer, roar, round window, rubber mallet, ruin, sack, savage, secondary eardrum, semicircular canals, shape, shell, slaughter, sledge, sledgehammer, slog, sow chaos, spank, stamp, stapes, steam hammer, stirrup, stone hammer, storm, stutter, tack hammer, tear, tear around, terrorize, thrash, thresh, thump, toil, travail, triphammer, tympanic cavity, tympanic membrane, tympanum, vandalize, vestibule, violate, wade through, wallop, whip, work away, wreck
Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1