A knife ( pl. : knives ; from Old Norse knifr 'knife, dirk' ) is a tool or weapon with a cutting edge or blade , usually attached to a handle or hilt . One of the earliest tools used by humanity, knives appeared at least 2.5 million years ago , as evidenced by the Oldowan tools. Originally made of wood, bone, and stone (such as flint and obsidian ), over the centuries, in step with improvements in both metallurgy and manufacturing, knife blades have been made from copper , bronze , iron , steel , ceramic , and titanium . Most modern knives have either fixed or folding blades; blade patterns and styles vary by maker and country of origin.
50-698: [REDACTED] Look up cuchillo in Wiktionary, the free dictionary. Cuchillo , a Spanish word for a knife , may refer to: Cuchillo (film) , a 1978 film with Mexican actor Andrés García Cuchillo, New Mexico , an unincorporated community Cuchillo-Có , a village in La Pampa Province in Argentina El Cuchillo , a village in Tinajo, Las Palmas province of western Lanzarote in
100-451: A tantō , a common Japanese knife. An athame , a ceremonial knife, is used in Wicca and derived forms of neopagan 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 being a sign of witchcraft . A common belief is that if a knife
150-431: A carbon content in the range of 0.30–1.70% by weight. Trace impurities of various other elements can significantly affect the quality of the resulting steel. Trace amounts of sulfur in particular make the steel red-short , that is, brittle and crumbly at high working temperatures. Low-alloy carbon steel, such as A36 grade, contains about 0.05% sulfur and melt around 1,426–1,538 °C (2,600–2,800 °F). Manganese
200-451: A combination of both. Single-edged knives may have a reverse edge or false edge occupying a section of the spine. These edges are usually serrated and are used to further enhance function. The handle, used to grip and manipulate the blade safely, may include a tang , a portion of the blade that extends into the handle. Knives are made with partial tangs (extending part way into the handle, known as "stick tangs") or full tangs (extending
250-406: A cradle, to protect the baby; knives were included in some Anglo-Saxon burial rites, so the dead would not be defenseless in the next world. 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
300-543: A higher cost of production. The applications best suited for the high carbon steels is its use in the spring industry, farm industry, and in the production of wide range of high-strength wires. The following classification method is based on the American AISI/SAE standard . Other international standards including DIN (Germany), GB (China), BS/EN (UK), AFNOR (France), UNI (Italy), SS (Sweden) , UNE (Spain), JIS (Japan), ASTM standards, and others. Carbon steel
350-463: A lamellar-pearlitic structure of iron carbide layers with α- ferrite (nearly pure iron) between. If it is hypereutectoid steel (more than 0.77 wt% C) then the structure is full pearlite with small grains (larger than the pearlite lamella) of cementite formed on the grain boundaries. A eutectoid steel (0.77% carbon) will have a pearlite structure throughout the grains with no cementite at the boundaries. The relative amounts of constituents are found using
400-453: A layered structure, combining the attributes of both. For example, a harder, more brittle steel may be pressed 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. Damascus steel is a form of pattern welding with similarities to laminate construction. Layers of different steel types are welded together, but then
450-776: A much finer microstructure, which improves the toughness. As the carbon content percentage rises, steel has the ability to become harder and stronger through heat treating ; however, it becomes less ductile . Regardless of the heat treatment, a higher carbon content reduces weldability . In carbon steels, the higher carbon content lowers the melting point. Carbon steel is often divided into two main categories: low-carbon steel and high-carbon steel. It may also contain other elements, such as manganese, phosphorus, sulfur, and silicon, which can affect its properties. Carbon steel can be easily machined and welded, making it versatile for various applications. It can also be heat treated to improve its strength, hardness, and durability. Carbon steel
500-557: 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. More exotic materials usually only seen on art or ceremonial knives include: Stone, bone, mammoth tooth, mammoth ivory, oosik (walrus penis bone), walrus tusk, antler (often called stag in a knife context), sheep horn, buffalo horn, teeth, and mop (mother of pearl or "pearl"). Many materials have been employed in knife handles. Handles may be adapted to accommodate
550-427: A sharp edge for years with no maintenance at all, but are fragile and will break if dropped on a hard surface or twisted in use. They can only be sharpened on silicon carbide sandpaper and appropriate grinding wheels. Plastic blades are not sharp and are usually serrated to enable them to cut. They are often disposable. Steel blades are commonly shaped by forging or stock removal. Forged blades are made by heating
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#1732797848170600-445: 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. Mass manufactured kitchen cutlery uses both
650-427: 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 incorporate the better attributes of carbon steel and stainless steel. High carbon stainless steel blades do not discolor or stain, and maintain a sharp edge. Laminated blades use multiple metals to create
700-601: A stud, hole, disk, or flipper located on the blade, all of which have the benefit of allowing the user to open the knife with one hand. The "wave" feature is another prominent design, which uses a part of the blade that protrudes outward to catch on one's pocket as it is drawn, thus opening the blade; this was patented by Ernest Emerson and is not only used on many of the Emerson knives, but also on knives produced by several other manufacturers, notably Spyderco and Cold Steel . Automatic or switchblade knives open using
750-412: A utility tool the knife can take many forms, including: 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. 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
800-472: A wavy, scalloped or saw-like blade. Serrated blades are more well suited for tasks that require aggressive 'sawing' motions, whereas plain edge blades are better suited for tasks that require push-through cuts (e.g., shaving, chopping, slicing). Many knives have holes in the blade for various uses. Holes are commonly drilled in blades to reduce friction while cutting, increase single-handed usability of pocket knives, and, for butchers' knives, allow hanging out of
850-536: Is a steel with carbon content from about 0.05 up to 2.1 percent by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: The term carbon steel may also be used in reference to steel which is not stainless steel ; in this use carbon steel may include alloy steels . High carbon steel has many different uses such as milling machines, cutting tools (such as chisels ) and high strength wires. These applications require
900-435: Is an OTF (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. A very common form of sliding knife is the sliding utility knife (commonly known as a stanley knife or boxcutter). The handles of knives can be made from
950-435: Is an environmentally friendly material, as it is easily recyclable and can be reused in various applications. It is energy-efficient to produce, as it requires less energy than other metals such as aluminium and copper. Mild steel (iron containing a small percentage of carbon, strong and tough but not readily tempered), also known as plain-carbon steel and low-carbon steel, is now the most common form of steel because its price
1000-399: Is broken down into four classes based on carbon content: Low-carbon steel has 0.05 to 0.15% carbon (plain carbon steel) content. Medium-carbon steel has approximately 0.3–0.5% carbon content. It balances ductility and strength and has good wear resistance. It is used for large parts, forging and automotive components. High-carbon steel has approximately 0.6 to 1.0% carbon content. It
1050-645: Is different from Wikidata All article disambiguation pages All disambiguation pages Knife Knives can serve various purposes. Hunters use a hunting knife , soldiers use the combat knife , scouts, campers, and hikers carry a pocketknife ; there are kitchen knives for preparing foods (the chef's knife , the paring knife, bread knife , cleaver ), table knife ( butter knives and steak knives ), weapons ( daggers or switchblades ), knives for throwing or juggling, and knives for religious ceremony or display (the kirpan ). A modern knife consists of: The blade edge can be plain or serrated , or
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#17327978481701100-561: Is given as a gift, the relationship of the giver and recipient will be severed. Something such as a small coin, dove or a valuable item is exchanged for the gift, rendering "payment." Some types of knives are restricted by law, and carrying of knives may be regulated, because they are often used in crime, although restrictions vary greatly by jurisdiction and type of knife. For example, some laws prohibit carrying knives in public while other laws prohibit possession of certain knives, such as switchblades . Carbon steel Carbon steel
1150-448: Is often added to improve the hardenability of low-carbon steels. These additions turn the material into a low-alloy steel by some definitions, but AISI 's definition of carbon steel allows up to 1.65% manganese by weight. There are two types of higher carbon steels which are high carbon steel and the ultra high carbon steel. The reason for the limited use of high carbon steel is that it has extremely poor ductility and weldability and has
1200-437: Is relatively low while it provides material properties that are acceptable for many applications. Mild steel contains approximately 0.05–0.30% carbon making it malleable and ductile. Mild steel has a relatively low tensile strength, but it is cheap and easy to form. Surface hardness can be increased with carburization . The density of mild steel is approximately 7.85 g/cm (7,850 kg/m ; 0.284 lb/cu in) and
1250-587: Is susceptible to rust and corrosion, especially in environments with high moisture levels and/or salt. It can be shielded from corrosion by coating it with paint, varnish, or other protective material. Alternatively, it can be made from a stainless steel alloy that contains chromium, which provides excellent corrosion resistance. Carbon steel can be alloyed with other elements to improve its properties, such as by adding chromium and/or nickel to improve its resistance to corrosion and oxidation or adding molybdenum to improve its strength and toughness at high temperatures. It
1300-409: Is to change the mechanical properties of steel, usually ductility, hardness, yield strength, or impact resistance. Note that the electrical and thermal conductivity are only slightly altered. As with most strengthening techniques for steel, Young's modulus (elasticity) is unaffected. All treatments of steel trade ductility for increased strength and vice versa. Iron has a higher solubility for carbon in
1350-466: Is transferred from the hook on the blade's tang to the hook on the rocker bar and thence to the small rocker pin. Excessive stress can shear one or both of these hooks rendering the knife effectively useless. Knife company Cold Steel uses a variant of the lock back called the Tri-Ad Lock which introduces a pin in front of the rocker bar to relieve stress on the rocker pin, has an elongated hole around
1400-412: Is used to mechanically strengthen the knife. 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. It holds its edge well, and remains easy to sharpen, but is vulnerable to rust and stains. Stainless steel is an alloy of iron, chromium , possibly nickel , and molybdenum , with only
1450-406: Is very strong, used for springs, edged tools, and high-strength wires. Ultra-high-carbon steel has approximately 1.25–2.0% carbon content. Steels that can be tempered to great hardness. Used for special purposes such as (non-industrial-purpose) knives, axles, and punches . Most steels with more than 2.5% carbon content are made using powder metallurgy . The purpose of heat treating carbon steel
1500-738: The Young's modulus is 200 GPa (29 × 10 ^ psi). Low-carbon steels display yield-point runout where the material has two yield points . The first yield point (or upper yield point) is higher than the second and the yield drops dramatically after the upper yield point. If a low-carbon steel is only stressed to some point between the upper and lower yield point then the surface develops Lüder bands . Low-carbon steels contain less carbon than other steels and are easier to cold-form, making them easier to handle. Typical applications of low carbon steel are car parts, pipes, construction, and food cans. High-tensile steels are low-carbon, or steels at
1550-400: The austenite phase; therefore all heat treatments, except spheroidizing and process annealing, start by heating the steel to a temperature at which the austenitic phase can exist. The steel is then quenched (heat drawn out) at a moderate to low rate allowing carbon to diffuse out of the austenite forming iron-carbide (cementite) and leaving ferrite, or at a high rate, trapping the carbon within
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1600-524: The lever rule . The following is a list of the types of heat treatments possible: Case hardening processes harden only the exterior of the steel part, creating a hard, wear-resistant skin (the "case") but preserving a tough and ductile interior. Carbon steels are not very hardenable meaning they can not be hardened throughout thick sections. Alloy steels have a better hardenability, so they can be through-hardened and do not require case hardening. This property of carbon steel can be beneficial, because it gives
1650-408: The liner lock , an L-shaped split in the liner allows part of the liner to move sideways from its resting position against the handle to the centre of the knife where it rests against the flat end of the tang. To disengage, this leaf spring is pushed so it again rests flush against the handle allowing the knife to rotate. A frame lock is functionally identical but instead of using a thin liner inside
1700-690: The Canary Islands a knife as used in Eskrima , an umbrella term for the traditional martial arts of the Philippines a character (a Mexican drug cartel enforcer) played by Danny Trejo in the film Predators , see : List of Predator characters See also [ edit ] Cuchillo Negro , the Spanish name of Baishan (c. 1816–1857), a Chihenne Apache chieftain Topics referred to by
1750-405: The blade is not released by means of a button or catch on the handle; rather, the blade itself is the actuator. Most assisted openers use flippers as their opening mechanism. Assisted opening knives can be as fast or faster than automatic knives to deploy. In the lock back , as in many folding knives, a stop pin acting on the top (or behind) the blade prevents it from rotating clockwise. A hook on
1800-404: The forging and stock removal processes. Forging tends to be reserved for manufacturers' more expensive product lines, and can often be distinguished from stock removal product lines by the presence of an integral bolster, though integral bolsters can be crafted through either shaping method. Knives are sharpened in various ways. Flat ground blades have a profile that tapers from the thick spine to
1850-488: The full length of the handle, often visible on top and bottom). There is also the enterçado construction method present in antique knives from Brazil, such as the Sorocaban Knife , which consists in riveting a repurposed blade to the ricasso of a bladeless handle. The handle may include a bolster, a piece of heavy material (usually metal) situated at the front or rear of the handle. The bolster, as its name suggests,
1900-425: The handle material uses a thicker piece of metal as the handle and the same split in it allows a section of the frame to press against the tang. A sliding knife is a knife that 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 this is the gravity knife ). Another form
1950-470: The handle of the knife on both sides allowing the user to slide the bolt backward freeing the knife to close. The Axis Lock used by knife maker Benchmade is functionally identical to the bolt lock except that it uses a cylinder rather than a rectangle to trap the blade. The Arc Lock by knife maker SOG is similar to the Axis Lock except the cylinder follows a curved path rather than a straight path. In
2000-452: The iron thus forming martensite. The rate at which the steel is cooled through the eutectoid temperature (about 727 °C or 1,341 °F) affects the rate at which carbon diffuses out of austenite and forms cementite. Generally speaking, cooling swiftly will leave iron carbide finely dispersed and produce a fine grained pearlite and cooling slowly will give a coarser pearlite. Cooling a hypoeutectoid steel (less than 0.77 wt% C) results in
2050-446: The lower end of the medium-carbon range, which have additional alloying ingredients in order to increase their strength, wear properties or specifically tensile strength . These alloying ingredients include chromium , molybdenum , silicon , manganese , nickel , and vanadium . Impurities such as phosphorus and sulfur have their maximum allowable content restricted. Carbon steels which can successfully undergo heat-treatment have
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2100-492: The needs of people with disabilities. For example, knife handles may be made thicker or with more cushioning for people with arthritis in their hands. A non-slip handle accommodates people with palmar hyperhidrosis . As a weapon, the knife is universally adopted as an essential tool. It is the essential element of a knife fight . For example: A primary aspect of the knife as a tool includes dining, used either in food preparation or as cutlery . Examples of this include: As
2150-428: The rocker pin to allow the mechanism to wear over time without losing strength and angles the hooks so that the faces no longer meet vertically. The bolt in the bolt lock is a rectangle of metal that is constrained to slide only back and forward. When the knife is open a spring biases the bolt to the forward position where it rests above the tang of the blade preventing the blade from closing. Small knobs extend through
2200-412: The same term [REDACTED] This disambiguation page lists articles associated with the title Cuchillo . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Cuchillo&oldid=932042902 " Category : Disambiguation pages Hidden categories: Short description
2250-489: 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. The resulting blade has a thinner edge, so it may have better cutting ability for shallow cuts, but it is lighter and less durable than flat ground blades and will tend to bind in deep cuts. Serrated blade knives have
2300-410: The stock is manipulated to create patterns in the steel. Titanium is a metal that has a better strength-to-weight ratio, is 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 hard, brittle, lightweight, and do not corrode: they may maintain
2350-476: 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 severely restricted by law in the UK and most American states. 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
2400-405: The tang of the blade engages with a hook on the rocker bar which prevents the blade from rotating counter-clockwise. The rocker bar is held in position by a torsion bar. To release the knife the rocker bar is pushed downwards as indicated and pivots around the rocker pin, lifting the hook and freeing the blade. When negative pressure (pushing down on the spine) is applied to the blade all the stress
2450-449: The user's hand, folding knives typically have a locking mechanism. Different locking mechanisms are favored by various individuals for reasons such as perceived strength (lock safety), legality, and ease of use. Popular locking mechanisms include: Another prominent feature of many folding knives is the opening mechanism. Traditional pocket knives and Swiss Army knives commonly employ the nail nick, while modern folding knives more often use
2500-411: The way when not in use. A fixed blade knife, sometimes called a sheath 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 moving parts. A folding knife connects the blade to the handle through a pivot , allowing the blade to fold into the handle. To prevent injury to the knife user through the blade accidentally closing on
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