Knife

A knife is a sharp-edged (single or double edged) instrument consisting of a thin blade used for cutting and fitted with a handle. The knife can be used as a tool or a weapon. Considered by some to be one of the most useful tools of all time, its origins date as far back as two-and-a-half million years ago, as evidenced by the Olduwan tools. Knives can be sharp or blunt. Blunt knives are not so good for cutting but can be used for spreading things like jam on bread.

History

The earliest knives were shaped by percussion flaking from rock, particularly water-worn creek cobbles made out of volcanic rock. During the Paleolithic era Homo habilis likely made similar tools out of wood, bone, and similar highly perishable material that has not survived. 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 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.

Materials and construction Main article: Knife making

Today, knives come in many forms but can be categorized between two different types: fixed blade knives and folding, or pocket, knives. Although each has inherent advantages, the two have many similar characteristics.

Modern knives consist of a blade (1) and handle (2). The blade can be fine or serrated. The handle, used to grip and manipulate the blade safely, may include the tang, a portion of the blade that extends into the handle. 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 the blade, and the bolster (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.

Blade

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.

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.

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.

Folding blade features

A folding knife can pivot, allowing the blade to fold into the handle. Although not likely to have a guard or full tang, 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 can be 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.

Another feature associated with the folding knife is a small knob, disk or hole that allows the user to open the knife with one hand, leaving the other hand free.

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, the knife is "slid" out of the handle, and locked into place. To retract the blade back into the handle, a release lever or button, or linerlock is pressed.

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. Wood handles provide good grip, but are more difficult to care for. They do not resist water well, and will crack or warp with prolonged exposure to water. Plastic handles are more easily cared for than wooden handle, but can be slippery and become brittle over time. Lighter than other materials, this may result in a knife that is unbalanced or too light. 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.

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, it can be found from the cradlea 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 babyto graveso the dead would not be defenseless in the next world. As such, 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. Samurai warriors, as part of bushido, could perform ritual suicide, or seppuku, with a tant?, a common Japanese knife. An athame, a ceremonial black-handled knife, is used in Wicca and other forms of modern witchcraft.

In Greece a black-handled knife placed under the pillow is used to keep away nightmares. As early as 1646 reference is made to a superstition of laying a knife across another piece of cutlery. 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."

Sources

Bayonet Knife

A knife bayonet is a knife or short sword which can be used both as a bayonet or fighting or utility knife. The knife bayonet became the almost universal form of bayonet in the 20th century due to its versatility and effectiveness. The socket bayonets proved useless when separate from the rifle and useless in trench warfare; and while versatile, sword bayonets proved to be impractical weapons in trench warfare because of their length.

The knife bayonets are basically long fighting knives or utility knives with an attachment point to rifle or assault rifle barrel. Almost all bayonets today are knife bayonets that are designed for use in hand-to-hand fighting and as utility knives, and some have serrated (saw-blade) back edges for utility.

Knife bayonets have 130 to 230 mm long and 15 to 25 mm wide blades, and are often fullered. They have been forged for durability and not breaking when twisting; this was often the problem with long and slender socket bayonets. Like sword bayonets, they can be used not only for thrusting, but also for cutting and slashing.

Combat Knife

Combat knives are mainly used in close combat.

Modern combat knives come in many shapes and sizes. Most militaries today have standardized the types of combat knives issued to infantry soldiers.

In the United States Marine Corps, the standard issue combat knife is the KA-BAR, and has been since World War II. A typical KA-BAR knife has a 7" clip-point blade. It is made of 1095 carbon steel and features a leather-washer or synthetic handle made of Kraton (a substitute for rubber, non-slip grip).

The famed Gurkha regiments favor the Kukri, a bladed weapon that more closely resembles a machete or Filipino bolo sword than a knife. With quick, chopping blows, a well trained Kukri wielder is devastating in close combat.

One famous combat knife is the British Fairbairn-Sykes, which is very much like a dagger in its thin, double-edged design. Its specific purpose is silently killing an unprepared sentry or other foe, or knife fighting.

Large knives meant for combat are also used extensively in jungle or swamp conditions, and are useful for actions such as cutting vines or roots.

Trench Knife

Trench knives are either purpose-made weapons, or are made from cut-down (shortened) bayonets or swords, and intended for close-quarter fighting, the design originating in the trench warfare of the First World War. They were particularly useful for trench raiding operations, along with other melee weapons

U.S. trench knives

Perhaps the most easily recognized American trench knife is the Mark I, introduced too late to see World War I service in the trenches, but adopted and carried by U.S. paratroopers in the Second World War. This knife was a full-tang design with a double-edged blade and a brass hilt incorporating a guard shaped as a knuckle duster, though the guard existed much more for the purpose of being a guard than for any perceived benefit as a punching aid. The pommel incorporated a 'skull-crusher' extension reputed to increase the flexibility and thus lethality of the weapon (although it should be noted that skull-crushers on other types of knife involve improper usage of the knife, "striking one's opponent with the pommel of one's knife is a dubious practice, the fanciful notion of those who have no real experience with knife fighting. Why not stab the fellow and be done with it?" and that use of the pommel rather than the blade is less lethal option).

The Mark I was preceded by the U.S. M1917 and M1918 trench knives, which featured more complex designs including a triangular stiletto blade, wooden grip, metal knuckle guard, and a rounded pommel. The two versions differed primarily in the construction and appearance of their knuckle guards.

The brass-hilted U.S. Mark I trench knives were made by three American companies -- Landers, Frary & Clark (L.F.&C.) of New Britain, CT; Henry Disston & Sons (HD&S) of Philadelphia, PA; and Oneida Community Limited (O.C.L.) -- and one French company (Au Lion/Societe General). American models of the Mark I are stamped on the right side of the brass grip "U.S. 1918", with the contractor's initials below that. These three American companies were among the four that also made the earlier U.S. M1917 and M1918 trench knives.

The French version of the Mark I is stamped on the blade ricasso with a recumbent lion, and "Au Lion" below that. The grip of the French version is typically stamped with "U.S. 1918". Several versions of the French model exist - some with grooves on top of the grip, some without. Some have letters and numbers cast into the knucks that are smaller than others.

The American Mark I knives and steel sheaths were issued with a blackened finish to prevent reflection, but some owners believing this to be tarnish attempted to polish them and remove the blackening. The French knives were not blackened, but their steel sheaths were blued. American versions of the Mark I appear to be better finished than the French version, and are slightly larger dimensionally as well. American-made sheaths for the Mark I trench knife are marked "L.F.&C. 1918", while the French sheath is unmarked. American-made knives have 8-sided skull-crusher pommels, the French model is 4-sided.

Other fighting knives used by U.S. forces are sometimes referred to as trench knives, indicating their purpose. These include the stiletto-shaped daggers carried by Marine Corps Raiders in World War II, and fighting-utility knives made by Ka-Bar and other manufacturers.

British & Commonwealth trench knives

The British Army and its Commonwealth allies (eg Australia, Canada & New Zealand) used a wide variety of trench knives during World War I. Some were privately purchased commercial models based on Bowie knives. Others were more specialised types eg push daggers with a roughly cylindrical aluminium grip which was shaped to fit comfortably when the user's hand made a fist. The attached 4 inch blade protruded between the knuckles of the user. It was common British practice for trench knives to be used in combination with other "quiet" weapons during trench raiding expeditions eg trench clubs, pick-axe handles and hatchets - backed up with revolvers and grenades. Years later, during the Second World War, the Fairbairn-Sykes Knife was widely issued to British commando type forces such as the Royal Marines, Parachute Regiment, Special Boat Service and the Special Air Service. Though not a true "trench knife" per se, the Fairbairn-Sykes was used for similar purposes.

German trench knives

The German Army used similar trench knives in the First and Second World Wars, often featuring a wooden or, in some cases, all-metal or composition plastic handle.

During World War I, some German trench knives were privately purchased, but many standardized versions were made by government contractors and officially issued. Most had slab wooden grips and metal sheaths and were sturdily made. According to one authoritative source, German-issued trench knives of World War I were "...conventional, general-purpose, cut-and-thrust knives..." with blades that were "...for the most part approximately six inches in length, single-edged with a top leading false edge...although double-edged blades are occasionally encountered."

German trench knives carried during World War II were similar in design and are usually known today as boot knives, although they seldom were carried in boots. Most also had steel sheaths but with clips that could be attached to boots or clothing, and most were made by government contractors and issued as combat gear.

Shiv Knife

A shiv (from the Romani word chiv) is a slang term for a sharp or pointed implement used as an improvised knife-like weapon. The shiv is the favored weapon of inmates in prisons across the world. It is infamous for its versatility - a shiv can be anything from a glass shard with cloth wrapped around one end to form a handle, to a razorblade stuck in the end of a toothbrush, to a sharpened spoon. Some inmates have even sharpened the ends of pork chop bones to make them into weapons.

A related term is shank. While the words are used interchangeably, the difference is that a shank is a type of shiv that is fashioned from the metal shank of a prison-issued boot or shoe. Since inmates were able to fashion effective shivs out of metal shanks, most (if not all) prisons no longer issue footwear with metal shanks. Shank is sometimes also used as a verb, meaning "To stab someone, usually with a shiv, multiple times in a quick succession." Another related term is the Scottish slang word, chib. To chib is to stab or slash with a sharp weapon. The weapon can also be called a chib.

Kitchen Knife

A kitchen knife is any knife that is intended to be used in food preparation. While much of this work can be accomplished with a few general-purpose knives, there are also many specialized knives that are designed for specific tasks. Kitchen knives can be made from several different materials.

Materials and Construction

Material Carbon Steel is an alloy of iron and carbon, often including other alloys such as vanadium and manganese. Carbon steel commonly used in knives has around 1.0% carbon (ex. AISI 1095). A typical carbon steel blade is very inexpensive, and can be very sharp, and hold its edge well. Carbon steel is normally easier to resharpen than most stainless steels, but is vulnerable to rust and stains. Some professional cooks, particularly those in Asia, are partial to carbon steel blades because of their reasonable cost, cutting power, and edge-holding ability; others find these advantages outweighed in the kitchen by the extra maintenance required, as these blades must be cleaned, dried, and lubricated after each use. New carbon-steel knives may also impart a metallic or "iron" flavor to acidic foods, though over time, the steel acquires a dark patina of oxidation which acts to block this process. Some people find patina a charming sign of age, while others find it unsightly. Stainless Steel is an alloy of iron, approximately 10-15% chromium, possibly nickel, and molybdenum, with only a small amount of carbon. Typical is 420 stainless, a high-chromium, low-end stainless steel alloy often used in flatware. Most consumer grades of low-carbon stainless are considerably softer than carbon steel and more expensive grades of stainless, and must be more frequently sharpened. Nor can these knives take as sharp an edge as carbon steel, though most are highly resistant to corrosion. The thin, flexible, shiny blades common in cheap kitchen knives are typically made of low-carbon, inexpensive stainless alloys. They are difficult to sharpen, so they are often made with serrations, which slows dulling and enables them to cut adequately when they do become dull. High Carbon Stainless Steel normally refers to higher-grade, stainless steel alloys with a certain amount of carbon, and is intended to combine the best attributes of carbon steel and ordinary stainless steel. High carbon stainless steel blades do not discolor or stain, and maintain a sharp edge. Most of these 'high-carbon' stainless blades also feature higher quality alloys than less expensive stainless knives, often including amounts of molybdenum, vanadium, cobalt, and other components intended to increase strength, edge-holding, and cutting ability. Examples of such steels include 440-C, AUS-8, AUS-10, ATS-34, ATS-55, and many others. Laminated blades attempt to use the best of multiple materials by creating a layered sandwich of different steel alloys (there are no laminated blades made of plastic or ceramic.) Such knives are a modern descendant of the ancient Japanese San Mai sword-making process, sometimes known in the West as 'Damascus steel'. Frequently a harder, more brittle steel is sandwiched between two softer, tougher steel alloys, so that the blade combines the attributes, to some extent, of both metals. Many higher-quality Japanese (San Mai) and Scandinavian blades are made in this way. A laminated blade's edge can often be made harder than an ordinary stainless steel knife, in turn facilitating a more acute grind on the cutting blade (thereby increasing the knife's cutting abilities). In more expensive Japanese san mai kitchen knives, a carbon steel core (usually of a chrome vanadium cobalt alloy) may be laminated with outer layers of alternating hard and soft stainless alloys (up to 65 or more), in order to reduce vulnerability to corrosion while maintaining strength and flexibility (though the carbon-steel edge may still be somewhat vulnerable to corrosion, depending upon its chromium content). Due to their varying construction, it is impossible to make any generalizations about them. Titanium is metal that is lighter, more wear resistant, and more flexible than steel, but also less hard and it will not take as sharp an edge. But carbides in the titanium alloy allow them to be heat-treated to a sufficient hardness. Titanium does not impart any flavor to food. It is typically expensive. Ceramic blades are incredibly hard blades; so hard that they will maintain a sharp edge for months or years with no maintenance at all. Like titanium, they do not impart any taste to food and are immune to corrosion. On the other hand, although ceramic blades can be sharpened on silicon carbide sandpaper or many grinding wheels, it is difficult enough that they are usually professionally sharpened. Also, they are hard enough to cut through glaze on dinnerware, so they should only be used on cutting boards. Further, although they are hard, ceramic blades are also very brittle, and will chip if struck against hard objects, or even sharpened improperly. Ceramic blades must never be used to pry or lever foods or other materials apart, as they may snap. Ceramic blades are very light in weight, though this light weight can frequently result in severe imbalance of blade and handle if not properly designed. Plastic blades are not very sharp at all. Their primary use is for cutting through vegetables such as lettuce without causing them to discolor (a steel knife will cause the cut edges of lettuce to turn black.) Plastic knives can cut skin, especially wet skin, but will not penetrate far into flesh, a boon for cooks. They cannot scratch dinnerware or cutting boards. They can be resharpened, but they are cheap enough that they are regarded as semi-disposable. They cannot be made as sharp as metal or ceramic blades, but since they are typically serrated, they may perform adequately for their intended purpose.

Blade

Steel blades can be manufactured either by being forged or stamped. Forged blades are made in an intricate, multi-step process, often by skilled manual labor. A chunk of solid or powdered steel alloy is heated to a high temperature, and pounded while hot to form it. The blade is then heated above critical temperature (which varies between alloys), quenched in an appropriate quenchant, and tempered to the desired hardness. After forging and heat treating, the blade is polished and sharpened. Forged blades are typically thicker and heavier than stamped blades, an advantage in some situations. Forged blades are often considered superior to stamped blades, and are often preferred by chefs. Stamped blades are cut to shape directly from cold rolled steel, heat-treated for strength, then ground, polished, and sharpened. Though they are not preferred by most professional chefs, several popular knife brands, such as Global, do use stamped and heat-treated blades in their premium knives. As the quality of rolled steel improves, they may approach the quality of forged blades. Stamped blades can often be identified by the absence of a bolster.

Edge For more details on this topic, see Grind.

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. They are heavier and tougher than a hollow ground knife. 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. 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 (such as bread or tomatoes) that might otherwise be ruined by a slightly dull knife with a plain, flat-ground edge. They are also particularly good on fibrous foods like celery or cabbage. Serrated knives cut much better than plain edge blade knives when dull, so they may go longer without sharpening (some serrated blades are claimed never to need sharpening.) However, they require specialized equipment and a different technique in order to resharpen them. Further, serrations are often used to improve the cutting ability of a less-expensive, soft stainless alloy blade, (usually incorporating an extremely thin blade design to reduce friction). For this reason, some professional chefs recommend buying at least a moderately-priced serrated knife made of high-carbon stainless, as these knives will inevitably dull and have to be replaced or resharpened. Some companies have names for their own serration patterns and apply them to an entire line of knives. Examples are Cutco's Double-D edge and Henckel's Eversharp Pro series. Granton Edge does not refer to the edge of a blade, strictly speaking. Granton edge or kullenschiff blades have a number of hollow scallops machined into one or both sides of the blade above the edge. These are normally found on meat carving knives, but have recently appeared on other types of knives, especially Western copies of the Japanese santoku. The granton edge is an attempt to improve the cutting and separation of sliced meats, cheese, and vegetables. Because the scallops tend to weaken blade strength, granton edges are normally found only on knives made of softer and less expensive single alloys of stainless steel.

Handle

The handles of kitchen knives can be made from a number of different materials, each of which has advantages and disadvantages. Wood handles provide good grip, and most people consider them to be the most attractive. They are, however, slightly more difficult to care for as they must be cleaned more thoroughly and occasionally treated with mineral oil. Most wood handles, especially those of ordinary varnished hardwood, do not resist water well, and will crack or warp with prolonged exposure to water. They should be hand-washed for that reason. Some people argue that ordinary varnished wood handles can harbor more microorganisms as the varnish layer wears off, thus requiring resealing or revarnishing to seal the wood's pores. Plastic handles are more easily cared for than wooden handles and do not absorb microorganisms. However, plastics may also be less resistant to ultraviolet damage and may become brittle over time, resulting in cracking. Some plastics are also slippery in the hand. The material is lighter than most other materials, which may result in a knife that is off-balance or too light for some tastes. Composite knives are made from laminated wood composites impregnated with plastic resin. Pakkawood and Staminawood are commonly encountered composite wood handles. They are considered by many chefs to be the best choice because they are as easy to care for and as sanitary as plastic, they have the appearance, weight, and grip of hardwood, and are more durable than either. They often have a laminated, polished appearance, and may have intense or varied coloring. Stainless Steel handles are the most durable of all handles, as well as the most sanitary. Many argue, however, that they are very slippery in the hand, especially when wet. To counter this, many premium knife makers make handles with ridges, bumps, or indentations to provide extra grip. One disadvantage of some all-metal handles is that knife weight usually goes up considerably, affecting the knife's balance and increasing hand and wrist fatigue.

Chefs Knife

In cooking, a chef's knife, also known as a French knife, is a cutting tool used in food preparation. The chef's knife is an evolution of the butcher knife, and was originally designed primarily to slice and disjoint large cuts of beef. Today it is the primary general-utility knife for most Western cooks.

A chef's knife generally has a blade eight-inches (20 cm) in length and 1 and a half inches in width, although individual models range from six to 12 inches (15 to 30 cm) in length. There are two types of blade shape, French and German. The far more common German design features a pronounced curve towards the tip of the blade which allows the knife to be rocked up and down, chopping the food with the belly and heel of the blade. The French design is more triangular, with much less curve at the tip and a longer straight section of blade; it is designed to be pulled towards the user, slicing the food instead. Neither style is inherently superior, personal preference will dictate the choice.

A modern chef's knife is a utility knife designed to perform well at many differing kitchen tasks, rather than excelling at any one in particular. It can be used for mincing, slicing, chopping vegetables, slicing meat, or even disjointing large cuts of beef or ham. In order to improve the chef's knife's multi-purpose abilities, some owners employ differential sharpening along the length of the blade. The fine tip, used for precision work such as mincing, might be ground with a very sharp, acute cutting bevel; the mid-section or belly of the blade receives a moderately sharp edge for general cutting, chopping and slicing, while the heavy heel or back of the cutting edge is given a strong, thick edge for such heavy-duty tasks as disjointing beef.

Recently, a Japanese development of the chef's knife, the santoku (literally: "three good things"), a general-purpose utility knife, has also gained popularity in the West. The santoku is primarily designed for cutting fish, vegetables, and boneless or lightly-boned meats such as chicken. The santoku features a sheepsfoot blade with a spine that drops sharply to meet the hardened, acutely-ground cutting edge.

Physical description

Materials

The blade of a chef's knife is made from one of these materials: Carbon steel: An alloy of iron and approximately 1% carbon. Most carbon steel chef's knives are simple carbon iron alloys without exotic additions such as chrome or vanadium. Carbon steel blades are both easier to sharpen than ordinary stainless steel and usually hold an edge longer, but it is vulnerable to rust and stains. Some professional cooks swear by knives of carbon steel because of their sharpness. Over time, a carbon-steel knife will normally acquire a dark patina, and can rust or corrode if not cared for properly by cleaning and lubricating the blade after use. Some chefs also 'rest' their carbon-steel knives for a day after use in order to restore the oxidizing patina, which prevents transfer of metallic tastes to some foods. While some cooks prefer and use carbon steel knives (especially in Asia and the Middle East), others find carbon steel too maintenance-intensive in a kitchen environment. Stainless steel: An alloy of iron, approximately 10-15% chromium, possibly nickel, and molybdenum, with only a small amount of carbon. Lower grades of stainless steel cannot take as sharp an edge as good-quality high-carbon steels, but are resistant to corrosion, do not taint food, and are inexpensive. Higher grade and 'exotic' stainless steels (mostly from Japan - as used by Global, Kasumi and others) are extremely sharp with excellent edge retention, and equal or outperform carbon steel blades, but they are expensive. Laminated. As noted above, all materials used in blades represent various compromises. A laminated knife tries to use the best of each material by creating a layered sandwich of different materials -- for instances, using a softer-but-tough steel as the backing material, and a sharper/harder - but more brittle - steel as the edge material. Ceramic blades hold an edge the longest of all, but they chip easily and will break if dropped. They also require special equipment and expertise to resharpen. They are sintered to shape with zirconium oxide powder. They are chemically nonreactive, so will not discolor or change the taste of food.

The handle may be made from: Wood Plastic Steel

Or any of a number of synthetic/composite materials.

The edge may be ground in different ways: V-shape Beveled edge. Hollow-ground.

Manufacturing

For a steel knife, there are two ways to fashion the blade. Hot-forged: A hot-forged blade is made in an intricate, multi-step process, often by skilled manual labor. A chunk of steel is heated to a high temperature, and beaten to shape the steel. After forging, the blade is ground down and sharpened. Forged knives are usually also full-tang, meaning the metal in the knife runs from the tip of the knifepoint to the far end of the handle. Stamped: A stamped blade is cut to shape directly from cold rolled steel, heat-treated for strength and temper, then ground, sharpened, and polished. Stamped blades lack the benefits of the toughness brought by forging, but are cheaper to produce. As the quality of rolled steel improves, they may approach the quality of hot-forged blades.

Buying a chef's knife

Someone in the market for a chef's knife will make a choice based on price, the cost of maintenance, and how the knife feels in the hand (often called the balance). Considered qualities may include cost, maintenance, cutting efficiency, edge geometry, corrosion resistance, and balance. Knife origin and culture also come into play. Typically, a Japanese chef's knife (gyuto) will possess different edge geometry and harder steels (60-62 Rc) than those of most Western manufacturers, thus allowing a more acute cutting angle.

Using a chef's knife

Technique for the use of a chef's knife is an individual preference. Nevertheless, professional chefs commonly follow certain practices.

Perhaps the most basic difference in technique has to do with how the cook physically places his or her hand on the knife. Some prefer a grip around only the handle, with all four fingers and the thumb gathered underneath as in a clenched fist. Others prefer a grip on the blade itself, with the thumb and the index finger grasping the blade just to the front of the finger guard and the middle finger placed just opposite, on the handle side of the finger guard below the bolster. The size and shape of the particular knife, and the job it is being used to do, are also important considerations.

Actually applying a chef's knife to different kinds of food in an effective way is a matter of demonstration and experience. For example, a good chef's knife can be used to dice both tomatoes and onions, but the characteristics of each vegetable require different motions with the knife which may not be immediately obvious without instruction. Some techniques seen on fast-paced cooking shows should likely not be attempted by anyone without professional experience.

Regardless of how the knife is being used, the cook should be mindful of their own comfort, safety and confidence when using a chef's knife: a knife in hurried hands can cause a nasty cut. A good motto is "Know where the sharp part is pointing," the sharp part being the entire edge from point to heel. Knowing how to hold the food that is being cut is equally as important as knowing how to hold the knife, as the hand not holding the knife is in a subtly obvious way the most likely to be cut. For example, when holding large items such as a head of lettuce, the thumb of the hand not holding the knife should never be tucked underneath.

Professional chefs may develop very close affiliations with their knives and may not allow others to use them under any circumstances. Knife preference, in terms of length, weight, brand, and nearly any other criterion, is often hotly debated in restaurant kitchens, but even cooks at home should carefully consider a potential knife. A good chef's knife can be a family heirloom as treasured as a cast-iron pan.

Extensive, ongoing use of a chef's knife may lead to a hardening at the base of the index finger sometimes called a "knife callus."

Bowie Knife

Bowie knife specifically refers to a style of knife designed by Colonel James "Jim" Bowie and originally created by James Black, though is commonly used to refer to any large sheath knife with a clip point.

Description

The historical Bowie was not a single design, but was a series of knives improved several times by Jim Bowie over the years.

The version most commonly known as the historical Bowie knife would usually have a blade of at least six inches (15cm) in length, some reaching 12 inches (30cm) or more, with a relatively broad blade that was an inch and a half to two inches wide (4 to 5 cm) and made of steel usually between 3/16" and 1/4" thick (from 4.8 to 6.4 millimeters). The back of the blade often had a strip of soft metal (normally brass or copper) inlaid intended to catch an opponent's blade, and also often had an upper guard that bent forward at an angle, also intended to catch an opponent's blade. The back edge of the curved clip point, also called the "false edge," was often sharpened in order to allow someone trained in European techniques of saber fencing to execute the maneuver called the "back cut" or "back slash." A brass quillon was attached to protect the hand, usually cast in a mold. It is likely that the blade shape was derived from the Spanish navaja clasp knives carried in Spain and the Spanish colonies in the Americas.

The shape and style of blade was chosen so that the Bowie knife could serve usefully as a camp and hunting tool as well as a weapon. Many knives and daggers existed that could serve well as weapons, and many knives existed that could serve well as tools for hunters and trappers, but the Bowie knife was designed to do both jobs well, and is still popular with hunters and sportsmen even in the present day.

The curved portion of the edge, toward the point, is for removing the skin from a carcass, and the straight portion of the edge, toward the guard, is for chores involving cutting slices, similar in concept to the traditional Finnish hunting knife, the "puukko" (though the typical early 19th Century Bowie knife was far larger and heavier than the typical puukko). The blade is generally long enough and heavy enough that the knife can be used as a hatchet or machete, but not so heavy or long as to be cumbersome. Most such knives intended for hunting are only sharpened on one edge, to reduce the danger of cutting oneself while butchering and skinning the carcass.

Since the 1960s, Bowie knives with sawteeth machined into the back side of the blade appeared inspired by the Air Force survival knife NSN: 7340-00-098-4327. The sawteeth were intended to cut through the Plexiglas canopy of a downed aircraft. During the Vietnam war the US Army issued them to helicopter crews for the same purpose.

History

The Sandbar Fight

The first knife Bowie became famous with was allegedly designed by Jim Bowie's brother Rezin in Avoyelles Parish, Louisiana, and smithed by blacksmith Jesse Cleft out of an old file. Period court documents indicate that Rezin Bowie and Cleft were well acquainted with one another. Rezin's granddaughter claimed in an 1885 letter to Louisiana State University that she personally witnessed Cleft make the knife for her grandfather.

This knife became famous as the knife used by Bowie at the Sandbar Fight, which was the famous 1827 duel between Bowie and several men, including a Major Norris Wright of Alexandria, Louisiana. The fight took place on a sandbar in the Mississippi River across from Natchez, Mississippi. In this battle Bowie was stabbed, shot, and beaten half to death but managed to win the fight.

Jim Bowie's older brother John claimed that the knife at the Sandbar Fight was not Cleft's knife, but a knife specifically made for Bowie by a blacksmith named Snowden.

James Black's Bowie Knife

The most famous version of the Bowie knife was designed by Jim Bowie and presented to Arkansas blacksmith James Black in the form of a carved wooden model in December of 1830. Black produced the knife ordered by Bowie, and at the same time created another based on Bowie's original design but with a sharpened edge on the curved top edge of the blade. Black offered Bowie his choice and Bowie chose the modified version. Knives like that one, with a blade shaped like that of the Bowie knife, but with half or more of the back edge sharpened, are today called "Sheffield Bowie" knives, because this blade shape became so popular that cutlery factories in Sheffield, England were mass-producing such knives for export to the U.S. by 1850, usually with a handle made from either hardwood, stag horn, or bone, and sometimes with a guard and other fittings of sterling silver.

Bowie returned, with his knife, to Texas and was involved in a knife fight with three men who had been hired to kill him. Bowie killed the three would-be assassins with his new knife and the fame of the knife was established. Legend holds that one man was almost decapitated, the second was disemboweled, and the third had his skull split open. Bowie died at the Battle of the Alamo five years later and both he and his knife became immensely famous. The fate of the original Bowie knife is unknown; however, a knife bearing the engraving "Bowie No. 1" has been acquired by the Historic Arkansas Museum from a Texas collector and has been attributed to Black through scientific analysis.

Black soon did a booming business making and selling these knives out of his shop in Washington, Arkansas. Black continued to refine his technique and improve the quality of the knife as he went. In 1839, Black was nearly blinded by an attacker and was no longer able to continue in his trade.

Black's knives were known to be exceedingly tough, yet flexible, and his technique has not been duplicated. Black kept his technique secret and did all of his work behind a leather curtain. Many claim that Black rediscovered the secret to producing true Damascus steel.

In 1870 at the age of 70, Black attempted to pass on his secret to the son of the family that had cared for him in his old age, Daniel Webster Jones. But Black had been retired for many years and found that he himself had forgotten the secret. Jones would later become Governor of Arkansas.

The birthplace of the Bowie knife is now part of the Old Washington Historic State Park which has over 40 restored historical buildings and other facilities including Black's shop. The park is known as "The Colonial Williamsburg of Arkansas". The American Bladesmithing Society has also established a college at the site to teach new apprentices, journeyman, and masters in the art of bladesmithing.

Variations and collecting

Over the years many knives have been called Bowie knives and the term has almost become a generic term for any large sheath knife. During the early days of the American Civil War Confederate soldiers carried immense knives called D-Guard Bowie knives. Many of these knives could have qualified as short swords and were often made at home from old saw or scythe blades.

Variations have become popular with collectors, possibly due to the appearance of such a knife in the first Rambo film with Sylvester Stallone. Knives with the sawtooth feature are still being made and sold, often called "survival knives," and incorporating a hollow handle that can theoretically be used to carry assorted survival gear. Despite many variations, it is quipped that for a knife to be considered a Bowie knife, it must be long enough to use as a sword, sharp enough to use as a razor, wide enough to use as a paddle, and heavy enough to use as a hatchet.

The Bowie knife is sometimes confused with the "Arkansas toothpick," possibly due to the interchangeable use of the names "Arkansas toothpick," "Bowie knife," and "Arkansas knife" in the antebellum period. The Arkansas toothpick is essentially a heavy dagger with a straight 15-25 inch blade. While balanced and weighted for throwing, the toothpick can also be used for thrusting and slashing. James Black is also credited with inventing the "Arkansas Toothpick" but no firm evidence exists for this claim.

The KA-BAR Knife of WWII fame is essentially based on the Bowie design.

A Bowie knife also appears on the shoulder sleeve insignia of the U.S. 39th Infantry Brigade, headquartered in Little Rock, Arkansas.

Balisong Knife

A balisong, otherwise known as a butterfly knife or a Batangas knife, is a folding pocket knife with two handles counter-rotating around the tang such that, when closed, the blade is concealed within grooves in the handles. In the hands of a trained user, the knife blade can be brought to bear quickly using one hand. Manipulations, called flipping, are performed for art or amusement.

Balisong

While the meaning of the term "balisong" is not entirely clear, a popular belief is that it is derived from the Tagalog Language words baling sungay (literally, "broken horn") as the original balisongs were made from carved animal horns. These knives are also referred to as "fan knives" or "click clacks." (See: Batangas Products)

The use of the balisong is so popular in the Philippines that an urban legend exists about every Batangue?o carrying it everywhere he goes. They are a pocket utility knife used by people of Filipino society. They have also been used to fight duels over matters of honor, although such practices have been discontinued for decades.

History

The butterfly knife appears first documented in a 1710 French book, "Le Perret", where an intricate and precise depiction of a butterfly knife is outlaid, explaining that the device was developed in the late 1500's as a utility knife. It then most likely came into popular use in the Philippines through transference intercontinentaly to Spain, which coincides with the Spanish governance of the Philippines during that period.

There is, however, conjecture attending to the balisong being an 'ancient Filipino invention dating back to 800 AD', stating it to be the most ancient of weapons of the Filipino fighting system of Eskrima.

Construction

There are two main types of balisong construction: sandwich construction and channel construction.

Sandwich constructed balisongs are assembled in layers that are generally pinned or screwed together. They allow the pivot pins to be adjusted tighter without binding. When the knife is closed, the blade rests between the layers.

For a channel constructed balisong, the main part of each handle is formed from one piece of material. In this handle, a groove is created (either by folding, milling, or being integrally cast) in which the blade rests when the knife is closed. This style is regarded as being stronger than sandwich construction.

Pocket Knife

A pocket knife is a folding knife with a blade that fits inside the handle and that is small enough to fit in a pocket. Blades are typically no larger than 3 to 5 in. (8 to 13 cm) in length. Pocket knives are very versatile tools, and may be used for anything from opening an envelope, to cutting twine, to slicing an apple.

Slipjoint knives

Most pocket knives for light duty are slipjoints. This means that the blade does not lock, but, once opened, is held in place by a spring device that allows the blade to fold if a certain amount of pressure is applied.

These knives often have more than one blade, including an assortment of knife blade types (serrated, plain edged, saws) as well as a myriad of other tools such as bottle openers, corkscrews, and scissors. A large tool selection is the signature of the Swiss Army Knife. These knives are produced by Victorinox and Wenger and issued to the army and sold to the public. The German Army knife is large but light, with two blades opening from each side. It has hard plastic grips and aluminum liners. The United States Army knife, made by the Camillus Cutlery Company, used to have carbon steel blades and brass liners (both vulnerable to corrosion), but is now more durable with all-stainless steel construction. It has four blades opening from the same side. The handle, as manufactured, has rough edges, but these can be rounded, yielding an excellent and versatile knife.

Another method of non-locking knife is the friction-folder. These use simple friction between the blade and scales to hold the blade in place once opened.

Some popular styles of blade shapes are: Clip the upper part of the blade is cut away convexly to form a sharp point directly in front of the handle. Spear edge and back curve together to a point Drop point similar to spear but not necessarily symmetrical Pen similar to a spear but smaller Sheep's foot wide with straight edge and no point, common on boats and ships Wharncliffe flat cutting edge with back curve, similar to sheep's foot but with longer curve Spay or spey clipped at the back to form a sort of point, but the clip is very short. These were originally for castrating live stock and are used for delicate work. Hook - The inside of the hook is sharp and the outside edge dull, so that a rope or animal skin can be cut without cutting the surface that the knife travels along. These blades are used by hunters for gutting animals and by emergency rescue people for cutting seat belts without harming the wearer.

There are many traditional types of folding knives:

A pen knife is a small and often thin knife with one or two pen blades, that does not interfere with the appearance of dress clothes, when carried in a pocket. They were originally intended for making and sharpening quill pens but are versatile and have remained fairly common. Knives with three or four knife blades are also common. A whittler is slightly larger than a pen knife and has three blades. A stockman has a clip, a sheep's foot and a spay blade. They are usually middle-sized. A trapper is large, with a clip and a spay blade. Another traditional styles is the Sodbuster.

Newer multitools have gained popularity in recent years:

The Leathermans and similar combination tools now compete with multi-bladed knives, but most of these are rather large for carrying in a pocket. The "main blade" is typically a pair of pliers and there is typically one non-locking knife blade.

The credit card knife is a very thin knife that is the shape and size of a credit card. It is designed to be carried in the wallet along with regular credit cards. Some of this shape of knife also contain other small tools, such as tweezers, or toothpicks.

Locking knives

The 1900s brought a new system to the knife world with the popularization of locking pocket knives. Companies such as Buck Knives, Benchmade, Camillus, Case, Gerber, Kershaw, Leatherman, Spyderco, and Opinel, to name a few, have created a wide range of products with locks of all types. The most popular form, the lockback knife (or buck knife) is a refinement of the slipjoint, where the spring along the back of the knife has a hook on it and the blade has a notch. When the blade is fully open the hook and notch align, locking the blade in place. Closing the blade requires the user releasing the blade to apply pressure to the back of the blade and in addition press on a lever located on the back of the knife handle to disengage the hook from the notch and thus release the blade. This locking mechanism adds a level of safety while cutting by preventing accidental closure. There are other types of locks; some of the more popular ones are the Walker Linerlock, the frame lock, where the bolster inside the knife is spring loaded to enagage the blade when open and thus hold it in place, and the Axis lock (a Benchmade patent). Even the Swiss Army knife product range has adopted the locks on their 111mm models. Leatherman and SOG tools are now available with locking blades.

Most slipjoint locking knives have only one blade, as large as can be fit in the handle. Because the locking mechanism relies on the spring along the back of the blade to lock it and it is difficult to have multiple levers for each blade. An electrician's knife typically has a locking screwdriver blade but a non-locking knife blade.

Other features

Traditional knives were opened using nail-nicks, or slots where the user's fingernail would enter to pull the blade out of the handle. This became somewhat cumbersome and required use of two hands, so there were innovations to remedy that. The thumb-stud, a small stud on the blade that allows for one-handed opening, led the way for yet more innovations, such as the opening hole (a Spyderco patent where the user presses the pad of his thumb against a hole and opens the blade by rotating his thumb similarly to using the thumb-stud), "assisted opening" systems pioneered by Ken Onion and his "Speed-Safe" mechanism, as well as Ernest Emerson's Wave system, where a hook catches the user's pocket upon removal and the blade is opened during a draw. One of the first one handed devices was the automatic spring release, also known as a switchblade.

Another innovation of Sal Glesser, Spyderco founder, was the clip system, which he named a "Clip-it". Clips are usually metal or plastic and similar to the clips found on pens except thicker. Clips allow the knife to be easily accessible, while keeping it lint-free and unscathed by pocket items such as coins.

Legal issues

Nearly all pocket knives are legal to own in most countries, but they increasingly face legal restrictions on their use. While pocket knives are almost always used as tools, they do have the potential to become weapons. In many places it is illegal to conceal knives larger than a certain size, or with certain locking or opening mechanisms. They are often banned or heavily restricted in secure areas, such as schools and airports. Switchblades and other "auto-openers" are banned from interstate shipment by the U.S. Government and prohibited entirely in many places, including 37 U.S. states, though nearly all statutes prohibiting switchblades allow an exception permitting ownership by the one-handed, the military and the police. It is illegal to carry knives of any type with blades over three inches in the UK, unless with good reason. Knives with blades of less than 3 inches may be carried if the blade is not fixed or capable of being locked (essentially, a slip joint knife like a Swiss Army knife), although a person behaving aggressively and in possession of any knife is likely to be in greater trouble.

Nevertheless, they retain a significant following, associated especially with the outdoors and those who enjoy camping, hunting, fishing, and so on. For example, the Boy Scouts of America offer merit badges that involve knife work, such as wood carving.

Palette Knife

A palette knife is a blunt knife with an extremely flexible steel blade and no sharpened cutting edge. It is primarily used for mixing paint colors, paste, etc., or for marbling, decorative endpapers, etc. The "palette" in the name is a reference to an artist's palette which is used for mixing oil paints. Certain artistic techniques call for painting with a palette knife.

Art palette knives come primarily in two types: symmetric knife resembling a putty knife with a rounded tip, suited for mixing paints on the palette; asymmetric knife with a pointed tip, lowered or "cranked" like a trowel, suited for painting on canvas.

Palette knives are also used in cooking, where their flexibility allows them to easily slide underneath pastries or other items. See frosting spatula.

Scalpel Knife

A scalpel is a very sharp knife used for surgery, anatomical dissection, and various arts and crafts. Scalpels may be disposable or re-usable. Re-usable scalpels can have attached, resharpenable blades or, more commonly, non-attached, replaceable blades. Disposable scalpels usually have a plastic handle with an extensible blade (like a utility knife) and are used once, then the entire instrument discarded.

Scalpel blades are usually of hardened and tempered steel. Medical blades are made of high carbon steel, while craft blades are made of stainless, but titanium, ceramic, diamond and even obsidian are not unknown. For example, when performing surgery under MRI guidance, metallic blades are unusable (the steel blades would be drawn to the magnets) or may cause image artifacts. Alternatives to scalpels in surgical applications include electrocautery and lasers.

Surgical scalpels

Surgical scalpels consist of two parts, a blade and a handle. The handles are reusable, with the blades being replaceable. In medical applications, each blade is only used once, (even if just for a single, small cut). Medical scalpel handles come in two basic types. The first is a flat handle used in the #3 and #4 handles. The #7 handle is more like a long writing pen, rounded at the front and flat at the back. A #4 handle is larger than a #3, and while some blades fit both others are too large or small and can only fit one or the other. The following table of blades is incomplete and some blades listed may work with handles not specified here.

Gripping a medical scalpel Palmar grip Also called the "dinner knife" grip. The handle is held with the second through fourth fingers and secured along the base of the thumb, with the index finger extended along the top rear of the blade and the thumb along the side of the handle. This grip is best for initial incisions and larger cuts. Pencil grip Best used for more precise cuts with smaller blades (e.g. #15) and the #7 handle. The scalpel is held with the tips of the first and second fingers and the tip of the thumb with the handle resting on the "anatomical snuff box," at the fleshy base of the index finger and thumb. Care should be taken not to allow the handle to rest too far along the index finger as this promotes an unstable grip and cramped fingers.

Safety Scalpels

In the last decade, a rising awareness of the dangers of sharps in a medical environment has led to the development of various methods of protecting healthcare workers from accidental cuts and puncture wounds. According to the CDC (the Centers for Disease Control and Prevention) as many as 1,000 people each day are subject to accidental needle sticks and lacerations while providing medical care . Companies like Bard-Parker and Shippert Medical Technologies offer lines of retractible-blade scalpels which protect users by covering the blade when not in use. Some such scalpels are disposable and others feature replaceable blades on re-usable metal handles.

Graphic design and arts and crafts blades

Graphical and model-making scalpels tend to have round handles, with textured grips (either knurled metal or soft plastic). These are often called by the name of the most well-known manufacturer of graphic arts blades, X-Acto knives. The blade is usually flat and straight, allowing it to be run easily against a straightedge to produce straight cuts.

There are many kinds of graphic arts blades, the most common around the graphic design studio is the #11 blade which is very similar to a #11 surgical blade (q.v.). Other blade shapes are used for wood carving, cutting leather and heavy fabric, etc.

Ancient Scalpels

Ancient Egyptians made incisions for embalming with scalpels of sharpened Obsidian and it is even used in modern times. Ayurveda mentions the use of sharp bamboo splinters.

Survival Knife

Survival knives are intended for survival purposes when lost in a wilderness environment. Military units frequently issue some type of survival knife. Hunters, hikers, and other outdoor sport enthusiasts also purchase and use great numbers of commercial survival knives. Some survival knives are heavy-bladed and thick; others are more lightweight or fold in order to save weight and bulk as part of a larger survival kit.

Origins of the survival knife

Previous to the late 19th century, outdoorsmen and military personnel did not use knives that were notably different from the knives used by butchers. Bladestock was relatively thin and the handles were often no more than two wooden slabs riveted to the tang. Around the turn of the century, Webster Marbles introduced the modern concept of the "hunting knife." These knives incorporated heavier blades, crossguards, and pommels. They very much resembled miniaturized Bowie knives. Case, Cattaraugus, and other cutlery manufacturers soon introduced similar knives of their own and it is from these that the modern concept of the survival knife is descended. These knives, along with machetes and bolos constituted survival knives as used by military, explorers, and outdoorsmen up through at least the 1930s.

During WWII, survival knives were issued to aircraft crew, as it was a real possibility that these personnel might be shot down over wilderness or behind enemy lines. Lifeboats aboard naval vessels also frequently contained survival kits including knives. These knives varied in design from one branch of the service to another and from one nation to another. The majority of them were simply commercial knives purchased in bulk by the military. From the Vietnam-era and to present, purpose-built survival knives evolved. The serrations often seen on more recent survival knives are intended to allow aircrewmen to cut their way free through the relatively thin metal skin of a crashed helicopter or airplane. They do not function well as woodsaws nor are they intended as such. Those knives that do include functional saw-teeth still suffer from lack of blade length limiting the thickness of what can be cut when used as a saw. Other features, such as hollow handles that could be used as storage space for matches or similar small items, began gaining popularity in the 1980s. Custom or semi-custom makers such as Jimmy Lile and Bo Randall are often credited with inventing those features, but all of them can be found individually in earlier commercial knives. The movie Rambo may legitimately be credited with having created the market demand for large, serrated, hollow-handled survival knives. Knives of that description are even sometimes referred to as Rambo knives.

Some militaries, including the US, have redesigned the bayonet used with their issued rifle to include survival knife features. Historically, bayonets had functioned poorly as field knives, due to being designed primarily to turn a rifle into a thrusting weapon and only secondarily (if at all) to work as a field knife. The newer models function more acceptably for mundane tasks while retaining the capability to be attached to the muzzle of the rifle.

It should be kept in mind, though, that virtually any knife can be a survival knife if it is the only knife one has during an emergency.

Utility Knife

A utility knife (also called a box cutter, a Stanley knife, a razor blade knife, a carpet knife, or a stationery knife) is a common tool used in various trades and crafts for a variety of purposes.

Such a knife generally consists of a simple and cheap holder, typically flat, approximately one inch (25 mm) wide and three to four inches (75 to 100 mm) long, and typically made of either metal or plastic. Some use standard razor blades, others specialised double-ended blades as in the illustration. The user can manually adjust how far the blade extends from the handle, so that for example the knife can be used to cut the tape sealing a package without damaging the contents of the package. When the blade becomes dull, it can be quickly reversed or switched for a new one. Spare blades are often stored in the hollow knife handle, and can be accessed by removing a screw and opening the handle. This type of tool is known in British English, Australian English, New Zealand English and Dutch as a Stanley knife, a genericized trademark named after one of the first manufacturers to create this kind of implement. The genuine Stanley knife has a cast-metal body, and comes both in retractable versions and in fixed blade versions which allow no depth adjustment. There have been a number of versions of the classic retractable Stanley No. 99. The current model is the 99E . Fixed blade versions are widely used for handcrafts. The blades for a utility knife come in both double and single ended versions, and are interchangeable with many but not all of the later copies. Specialised blades also exist for cutting string, linoleum and other purposes. Spare or used blades may be stored in the handle.

Another style is one in which a handle, usually of plastic, contains a long, segmented blade which slides out from it. As the endmost edge becomes dull, it can be snapped off from the rest of the blade, exposing the next section which is sharp and ready for use. When all the individual segments are used, it is thrown away or a replacement blade is inserted. This kind often comes in bright colors like orange, blue and yellow. In Britain these are called wallpaper knives.

A style that is often used for the cutting of boxes consists of a simple sleeve around a rectangular handle into which single-edge razor blades can be inserted. The sleeve slides up and down on the handle, holding the blade in place during use and covering the blade when not in use.

Utility knives as weapons

Though such knives are not usually considered weapons, it was suggested by certain United States government officials that "box-cutter knives" were used in the September 11, 2001, terrorist attacks against that country. However, the exact design of these knives is unclear. (See Airport security repercussions due to the September 11, 2001 attacks for further discussion.)

They have also been used by minor criminals in muggings, and some schools ban their possession on school grounds; a campaign against the sale of box-cutter knives to young people was initiated in New York City by Mayor Rudy Giuliani in the 1990s.

On June 1, 2004, Japanese elementary school student Satomi Mitarai was stabbed to death by "Nevada-tan," an unnamed classmate, using a segmented-type utility knife.

In Australia, it is illegal to sell a cutting implement such as a utility knife to anyone under 16 years of age, and proof of age is often demanded of purchasers.

Recently, in the United Kingdom, there have been plans to raise the age limit for purchasing knives, including utility knives, from 16 to 18, in an effort to tackle "yob culture."

In Israel and Switzerland, these knives are known as Japanese knives.