Knife

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A knife is a hand held sharp-edged instrument consisting of handle attached to a blade used for cutting. The knife is a tool that can be used as a weapon. Its origins date as far back as two-and-a-half million years ago, as evidenced by the Oldowan tools.[1][2]

Contents

[edit] History

Image:The knife Grinder - 1853.jpg
The Knife Grinder - Drawn by P. Weenix and engraving by W. French - Published for the Proprietors by AH Payne, Dresden & Leipzig - 1853 (From the Dr. Nuno Carvalho de Sousa Private Collections - Lisbon)

The earliest knives were shaped by percussive flaking of rock, particularly harder rocks such as obsidian and flint. During the Paleolithic era Homo habilis likely made similar tools out of wood, bone, and similar highly perishable materials that have not survived.[2][3] As recent as five thousand years ago, as advances in metallurgy progressed, stone, wood, and bone blades were gradually succeeded by copper, bronze, iron, and eventually steel. Modern knives may be made from many different materials such as alloy tool steels, carbon fiber, ceramics, and titanium. Knives gained prominence during the Middle Ages as one of the three major items of cutlery in the western world, accompanying the fork and spoon, and in this way much of the world's population is exposed to knives on a daily basis. There is a very active community of modern custom knife makers and collectors. The American Bladesmith Society promotes forged blades; the Knifemakers Guild promotes all custom knives.

[edit] Materials and construction

Main article: Knife making

Today, knives come in many forms but can be categorized between two broad types: fixed blade knives and folding, or pocket, knives.

Image:Knife parts.jpg
Characteristic parts of the knife

Modern knives consist of a blade (1) and handle (2). The blade edge can be plain or serrated or a combination of both. The handle, used to grip and manipulate the blade safely, may include the tang, a portion of the blade that extends into the handle. Knives are made with partial (extending part way into the handle) and full (extending the full length of the handle, often visible on top and bottom) tangs. The handle can also include a bolster, which is a piece of material used to balance the knife, usually brass or other metal, at the front of the handle where it meets the blade. The blade consists of the point (3), the end of the knife used for piercing, the edge (4), the cutting surface of the knife extending from the point to the heel, the grind (5), the cross-section shape of the blade, the spine, (6), the top, thicker portion of the blade, the fuller (7), the groove added to lighten and stiffen the blade, and the ricasso (8), the thick portion of the blade joining the blade and the handle. The guard (9) is a barrier between the blade and the handle which protects the hand from an opponent, or the blade of the knife itself. A choil, where the blade is unsharpened and possibly indented as it meets the handle, may be used to prevent scratches to the handle when sharpening or as a forward-finger grip. The end of the handle, or butt (10), may allow a lanyard (11), used to secure the knife to the wrist, or a portion of the tang to protrude as a striking surface for pounding or glass breaking.[4][5]

[edit] Blade

Main article: Blade
Image:Chinese knife factory.jpg
Knife blade mass production in Guangzhou, China.

Knife blades can be manufactured from a variety of materials, each of which has advantages and disadvantages. Carbon steel, an alloy of iron and carbon, can be very sharp, hold its edge well, and remain easy to sharpen, but is vulnerable to rust and stains. Stainless steel is an alloy of iron, chromium, possibly nickel, and molybdenum, with only a small amount of carbon. It is not able to take quite as sharp an edge as carbon steel, but is highly resistant to corrosion. High carbon stainless steel is stainless steel with a higher amount of carbon, intended to combine the best attributes of carbon steel and stainless steel. High carbon stainless steel blades do not discolor or stain, and maintain a sharp edge. Laminate blades use multiple metals to create a layered sandwich, combining the attributes of both. For example, a harder, more brittle steel may be sandwiched between an outer layer of softer, tougher, stainless steel to reduce vulnerability to corrosion. In this case, however, the part most affected by corrosion, the edge, is still vulnerable. Pattern-welding is similar to laminate construction. Layers of different steel types are welded together, but then the stock is manipulated to create patterns in the steel. Titanium is metal that is lighter, more wear resistant, and more flexible than steel. Although less hard and unable to take as sharp an edge, carbides in the titanium alloy allow them to be heat-treated to a sufficient hardness. Ceramic blades are incredibly hard, lightweight blades; so hard that they will maintain a sharp edge for months or years with no maintenance at all. They are immune to corrosion, but can only be sharpened on silicon carbide sandpaper and some grinding wheels. Plastic blades are not very sharp at all but are typically serrated, and are usually considered disposable.[6]

Steel blades are commonly shaped by forging or stock removal. Forged blades are made by heating a single piece of steel, then shaping the metal while hot using a hammer or press. Stock removal blades are shaped by grinding and removing metal. With both methods, after shaping, the steel must be heat treated. This involves heating the steel above its critical point, then quenching the blade to harden it. After hardening, the blade is tempered to remove stresses and make the blade tougher. With common kitchen cutlery, forged blades are often seen in more expensive knives. Forged blades can often be distinguished from stock removal blades by the presence of an integral bolster.

The edge of the knife can be sharpened to a cutting surface in a number of different ways. Flat ground blades have a profile that tapers from the thick spine to the sharp edge in a straight or convex line. Seen in cross section, the blade would form a long, thin triangle, or where the taper does not extend to the back of the blade, a long thin rectangle with one peaked side. Hollow ground blades have concave, beveled edges that are ground starting midway down the blade, instead of at the spine. The resulting blade has a thinner edge, so it may have better cutting ability, but it is lighter and less durable than flat ground blades. Serrated blade knives have a wavy, scalloped or saw-like blade. Serrations make knives ideal for cutting things that are hard on the outside and soft on the inside that might otherwise be damaged by a knife with a plain edge blade. Serrated knives cut much better than plain edge blade knives when dull, so they may last longer without sharpening, and require a special tool to be sharpened.

[edit] Fixed blade features

A fixed blade knife does not fold or slide, and is typically stronger due to the tang, the extension of the blade into the handle, and lack of movable parts.[6]

[edit] Folding blade features

A folding knife can pivot, allowing the blade to fold into the handle. Although not likely to have a guard, folding knives typically have a locking mechanism. One common mechanism, found traditionally on pocket knives, is the slip joint. Once opened, the blade does not lock, but is held in place by a spring device that allows the blade to fold if a certain amount of pressure is applied. Alternately, the lockback or spine lock is often used. Like the slip-joint the lockback includes a pivoted latch connected to a spring, and can be disengaged only by pressing the latch down to release the blade.[6] Other common locking mechanisms for folding blades include liner locks, frame locks, button locks, and axis locks.

Another feature associated with many folding knives is a small stud or hole on the blade that allows the user to open the knife with one hand.

Automatic or switchblade knives open using the stored energy from a spring that is released when the user presses a button or lever or other actuator built into the handle of the knife. Automatic knives are popular amongst law enforcement and military users for their ease of rapid deployment and their ability to be opened using only one hand.

Increasingly common are assisted opening knives which use springs to propel the blade once the user has moved it past a certain angle. These differ from automatic or switchblade knives in that the blade is not released by means of a button or catch on the handle, rather the blade itself is the actuator. Assisted opening knives are often as fast or faster than automatic knives to deploy.

[edit] Sliding blade features

A sliding knife is a knife which can be opened by sliding the knife blade out the front of the handle. One method of opening is where the blade exits out the front of the handle point-first and then is locked into place (an example of the this is the gravity knife). Another form is a O-T-F (out-the-front) switchblade, which only requires the push of a button or spring to cause the blade to slide out of the handle, and lock into place. To retract the blade back into the handle, a release lever or button, usually the same control as to open, is pressed.

[edit] Handle

Main article: Handle (grip)

The handles of knives can be made from a number of different materials, each of which has advantages and disadvantages. Handles are produced in a wide variety of shapes and styles. Handles are often textured to enhance grip.

  • Wood handles provide good grip and are warm in the hand, but are more difficult to care for. They do not resist water well, and will crack or warp with prolonged exposure to water. Modern stabilized and laminated woods have largely overcome these problems. Many beautiful and exotic hardwoods are employed in the manufacture of custom and some production knives.
  • Plastic handles are more easily cared for than wooden handles, but can be slippery and become brittle over time.
  • Rubber handles such as Kraton or Respirine-C are generally preferred over plastic due to their durable and cushioning nature.
  • Micarta is a very popular handle material on user knives due to its extreme toughness and stability. Micarta is impervious to water, is grippy when wet, and is an excellent insulator. Micarta has come to refer to almost any fibrous material cast in resin. There are many varieties of micarta available. One very popular version is a fibreglass impregnated resin called G-10.
  • Leather handles are seen on some hunting and military knives, notably the KA-BAR. Leather handles are typically produced by stacking leather washers, or less commonly, as a sleeve surrounding another handle material.
  • Skeleton handles refers to the practice of using the tang itself as the handle, usually with sections of material removed to reduce weight. Skeleton handled knives are often wrapped with parachute cord or other wrapping materials to enhance grip.
  • Stainless steel handles are durable and sanitary, but can be slippery. To counter this, many premium knife makers make handles with ridges, bumps, or indentations to provide extra grip. Steel handles are typically only seen on consumer kitchen knives, or as a bare tang.

More exotic materials usually only seen on art or ceremonial knives include: Stone, bone, mammoth tooth, mammoth ivory, oosic (walrus penis bone), walrus tusk, antler (often called stag in a knife context), sheep horn, buffalo horn, teeth, etc. Almost any hard material can (and has been) employed as a knife handle.

[edit] Types of knives

For more details on the various types of knives, see Blade#Patterns of knife blades.

[edit] Knives as weapons

As a weapon, the knife is universally adopted as an essential tool. For example:

  • Bayonet: A knife-shaped close-quarters fighting weapon designed to fit over the muzzle of a rifle barrel or similar weapon
  • Combat knife: Any knife intended to be used mainly for fighting
  • Trench knife: Purpose-made or improvised knives, intended for close-quarter fighting, particularly in trench warfare
  • Shiv: A crudely made homemade knife out of everyday materials, especially prevalent in prisons among inmates. An alternate name in some prisons is Shank
  • Switchblade: A knife with a folding blade that springs out of the grip when a button or lever on the grip is pressed

[edit] Knives as utensils

A primary aspect of the knife as a tool includes dining, used either in food preparation or as cutlery. Examples of this include:

[edit] Knives as tools

As a utility tool the knife can take many forms, including:[6]

  • Bowie knife: Commonly, any large sheath knife, or a specific style of knife designed by Colonel Jim Bowie
  • Butterfly knife: A folding knife also known as a balisong, with two handles counter-rotating around the tang such that, when closed, the blade is concealed within the handles

[edit] Knives as a tradition

  • Athame: A, typically black-handled and double-edged, knife used in ceremonial magic, Wicca and other forms of magic derived from them.
  • Kukri: A Nepalese knife used as both tool and weapon
  • Laguiole knife: A traditional French pocket-knife, originally produced in the town of Laguiole in the Aveyron region of southern France in the early 19th century
  • Lajinaa: A small spear, sometimes used in close range battles, used mostly by Spaniard pirates who raided trade ships in the gulf coast
  • Mora knife: Similar in design to Finnish puukkos, a range of belt-knives manufactured by the cutleries of the town of Mora in Dalarna, Sweden
  • Opinel knife: A simple, inexpensive, wooden pocket-knife, manufactured since the 1890s in the town of Saint-Jean-de-Maurienne in the Savoie region of France
  • Puukko: A traditional Finnish or Scandinavian style woodcraft belt-knife used as a tool rather than a weapon
  • Sabatier: A cooking knife manufactured in Thiers, France from well established manufacturers from the early 19th century
  • Seax: A Germanic single-edged knife, used primarily as a tool, but may also have been a weapon
  • Swiss Army knife: A brand of multiple-purpose pocket tool (see Pocket Knife above), usually containing several blades of different lengths, a corkscrew, a can-opener, a toothpick, tongs and even a little wood-saw and scissors sometimes. It was created in 1891 for the Swiss military.
  • Sgian Dubh: A small dagger traditionally worn with highland dress (kilt)

[edit] Rituals and superstitions

The knife plays a significant role in some cultures through ritual and superstition, as the knife was an essential tool for survival since early man.[2] Knife symbols can be found in various cultures to symbolize all stages of life; for example, a knife placed under the bed while giving birth is said to ease the pain, or, stuck into the headboard of a cradle, to protect the baby.[7][8]; knives were included in some Anglo-Saxon burial rites, so the dead would not be defenseless in the next world.[9][10][11] The knife plays an important role in some initiation rites, and many cultures perform rituals with a variety of knives, including the ceremonial sacrifices of animals.[12] Samurai warriors, as part of bushido, could perform ritual suicide, or seppuku, with a tantō, a common Japanese knife.[13] An athame, a ceremonial black-handled knife, is used in Wicca and other forms of neo-paganism.[14][15]

In Greece a black-handled knife placed under the pillow is used to keep away nightmares.[16] As early as 1646 reference is made to a superstition of laying a knife across another piece of cutlery being a sign of witchcraft.[17] A common belief is that if a knife is given as a gift, the relationship of the giver and recipient will be severed. Something such as a small coin is exchanged for the gift, rendering "payment."[8]

[edit] Legislation

Main article: Knife legislation

Knives are typically restricted by law, although restrictions vary greatly by country or state and type of knife. For example, some laws restrict carrying an unconcealed knife in public while other laws can restrict even private ownership of certain knives, such as switchblades.

[edit] Further reading

[edit] References

[edit] See also

[edit] External links

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Knife

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