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54-536: The plowshare itself is often a hardened blade dressed into an integral moldboard (by the blacksmith ) so making a unified combination of plowshare and moldboard, the whole being responsible for entering the cleft in the earth (made by the coulter's first cutting-through) and turning the earth over. In well-tilled terrain the plowshare may do duty without a preceding coulter. In modern plows both coulter and plowshare are detachable for easy replacement when worn or broken. Triangular-shaped stone plowshares are found at

108-469: A ban on import or possession of ballistic knives quickly gained traction. In September 1986 senators supporting the ballistic knife ban attached their bill to popular legislation designed to eradicate drug crops in foreign countries and halt international drug trafficking operations. The bill was subsequently enacted into law. The new federal statute prohibited future importation or possession of such knives in interstate commerce. Some individual states following

162-715: A blade propelled by an explosive charge falls outside the Federal law pertaining to these devices, but still may be restricted as this makes it a firearm subject to the Any Other Weapons (AOW) category of the National Firearms Act . Possession of ballistic knives and pilum knives is illegal under current legislation in the United Kingdom. and this has resulted in a tendency to interpret any bladed object of questionable status as falling within

216-555: A blade which opens automatically by hand pressure applied to a button, spring or other device in or attached to the handle of the knife." The Knives Act 1997 prohibits the marketing of knives as offensive weapons, while the Criminal Justice Act 1988 prohibits the carrying of blades or sharply pointed objects in a public place without "good reason or lawful authority". Finally, the Prevention of Crime Act 1953 prohibits

270-417: A body that is tough. Prehistorically, and in less technologically advanced cultures even into modern times, tool and weapon blades have been made from wood, bone, and stone. Most woods are exceptionally poor at holding edges and bone and stone suffer from brittleness making them suffer from fracture when striking or struck. In modern times stone, in the form of obsidian, is used in some medical scalpels as it

324-588: A congressional witness that ballistic knives could be used to defeat body armor typically worn by police officers, and witnessing a staged demonstration against a wood-backed target, Senator Alphonse D'Amato of New York introduced the Ballistic Knife Prohibition Act , a bill to ban sale or possession of ballistic knives. The bill eventually failed. However, after gaining the support of Senators Strom Thurmond of South Carolina, and Dennis DeConcini of Arizona, congressional support for

378-469: A convex section to avoid getting stuck in the wood where chopping axes can be flat or even concave. A khopesh , falchion , or kukri is angled and/or weighted at the distal end so that force is concentrated at the faster moving, heavier part of the blade maximizing cutting power and making it largely unsuitable for thrusting, whereas a rapier is thin and tapered allowing it to pierce and be moved with more agility while reducing its chopping power compared to

432-503: A distance of several meters / yards by pressing a trigger or operating a lever or switch on the handle. Spring-powered ballistic knives first appeared in books and press reports on Soviet and Eastern Bloc armed forces in the late 1970s. Commercially-produced ballistic knives briefly gained notoriety in the United States in the mid-1980s after they were marketed and sold in the United States and other Western countries. Since then,

486-571: A given state is legal (many states have statutes that regulate or prohibit the acquisition or possession of ballistic knives, and penalties vary from state to state). Like the federal switchblade law, an exception is made for sale to the United States Armed Forces within the confines of a contract , as well as possession by duly-authorized members of the Armed Forces in performance of their duty. A ballistic knife with

540-418: A low elastic modulus (is soft) but high yield strain (loosely, can be stretched or squashed by a large proportion without breaking), drawing serrations across the loaf with little downward force will allow each serration to simultaneously cut the bread with much less deformation of the loaf. Similarly, pushing on a rope tends to squash the rope while drawing serrations across it sheers the rope fibers. Drawing

594-404: A material into dust along a narrow channel, the kerf , whereas knives and similar act by forcing the material apart. This means that saws result in a loss of material and the serrations of a saw also serve to carry metal swarf and sawdust out of the cut channel.) Fullers are longitudinal channels either forged into the blade or later machined/milled out of the blade though the latter process

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648-423: A material that is about as hard , though usually harder, than the material to be cut. Insufficiently hard blades will be unable to cut a material or will wear away quickly as hardness is related to a material's ability to resist abrasion . However, blades must also be tough enough to resist the dynamic load of impact and as a general rule the harder a blade the less tough (the more brittle) a material. For example,

702-519: A proper cut without an edge, and so in competitive fencing such attacks reward no points. Some variations include: Blades are sometimes marked or inscribed, for decorative purposes, or with the mark of either the maker or the owner. Blade decorations are often realized in inlay in some precious metal (gold or silver). Early blade inscriptions are known from the Bronze Age , a Hittite sword found at Hattusa bears an inscription chiseled into

756-416: A separate crime to use or possess a ballistic knife during the commission of a federal crime of violence , with a minimum sentence of five years in a federal prison. Federal law does not prohibit the possession, manufacture, or sale of a ballistic knife within a state's boundaries, and the individual laws of each state or territory must be consulted to determine whether possession, manufacture, or sale within

810-414: A significant place both historically and in contemporary society, reflecting an evolution in material technology and utility. During food preparation, knives are mainly used for slicing, chopping, and piercing. In combat, a blade may be used to slash or puncture, and may also be thrown or otherwise propelled . The function is to sever a nerve, muscle or tendon fibers, or blood vessel to disable or kill

864-399: A similarly sized sword. A serrated edge, such as on a saw or a bread knife , concentrates force onto the tips of the serrations which increases pressure as well as allowing soft or fibrous material (like wood, rope, bread, and vegetables) to expand into the spaces between serrations. Whereas pushing any knife, even a bread knife, down onto a bread loaf will just squash the loaf as bread has

918-547: A smooth blade is less effective as the blade is parallel to the direction draw but the serrations of a serrated blade are at an angle to the fibers. Serrations on knives are often symmetric allowing the blade to cut on both the forward and reverse strokes of a cut, a notable exception being Veff serrations which are designed to maximize cutting power while moving the blade away from the user. Saw blade serrations, for both wood and metal, are typically asymmetrical so that they cut while moving in only one direction. (Saws act by abrading

972-413: A steel axehead is much harder than the wood it is intended to cut and is sufficiently tough to resist the impact resulting when swung against a tree while a ceramic kitchen knife, harder than steel, is very brittle (has low toughness) and can easily shatter if dropped onto the floor or twisted while inside the food it is cutting or carelessly stored under other kitchen utensils. This creates a tension between

1026-408: A thinner one of similar design while also making it experience more drag while slicing or piercing. A filleting knife will be thin enough to be very flexible while a carving knife will be thicker and stiffer; a dagger will be thin so it can pierce, while a camping knife will be thicker so it can be stronger and more durable. A strongly curved edge, like a talwar , will allow the user to draw the edge of

1080-568: A wide range of physical and chemical properties desirable for blades. For example, surgical scalpels are often made of stainless steel so that they remain free of rust and largely chemically inert; tool steels are hard and impact resistant (and often expensive as retaining toughness and hardness requires expensive alloying materials, and, being hard, they are difficult to make into their finished shape) and some are designed to resist changes to their physical properties at high temperatures. Steels can be further heat treated to optimize their toughness, which

1134-418: Is applied it them, forming a section like the bottom part of a letter "J". For this reason, straight edge razors are frequently stropped to straighten the edge. Drawing a blade across any material tends to abrade both the blade, usually making it duller, and the cut material. Though softer than glass or many types of stone used in the kitchen, steel edges can still scratch these surfaces. The resulting scratch

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1188-414: Is applied to the blade, either from the handle or pressing on the back of the blade. The handle or back of the blade has a large area compared to the fine edge. This concentration of applied force onto the small edge area increases the pressure exerted by the edge. It is this high pressure that allows a blade to cut through a material by breaking the bonds between the molecules, crystals, fibers, etc. in

1242-461: Is capable of being formed into an exceedingly fine edge. Ceramic knives are non-metallic and non-magnetic. As non-metals do not corrode they remain rust and corrosion free but they suffer from similar faults as stone and bone, being rather brittle and almost entirely inflexible. They are harder than metal knives and so more difficult to sharpen, and some ceramic knives may be as hard or harder than some sharpening stones. For example, synthetic sapphire

1296-448: Is full of very fine particles of ground glass or stone which will very quickly abrade the blade's edge and so dull it. In times when swords were regularly used in warfare, they required frequent sharpening because of dulling from contact with rigid armor, mail, metal rimmed shields, or other swords, for example. Particularly, hitting the edge of another sword by accident or in an emergency could chip away metal and even cause cracks through

1350-717: Is harder than natural sharpening stones and is as hard as alumina sharpening stones. Zirconium dioxide is also harder than garnet sharpening stones and is nearly as hard as alumina. Both require diamond stones or silicon carbide stones to sharpen and care has to be taken to avoid chipping the blade. As such ceramic knives are seldom used outside of a kitchen and they are still quite uncommon. Plastic knives are difficult to make sharp and poorly retain an edge. They are largely used as low cost, disposable utensils or as children's utensils or in environments such as air travel where metal blades are prohibited. They are often serrated to compensate for their general lack of sharpness but, as evidenced by

1404-477: Is important for impact blades, or their hardness, which allows them to retain an edge well with use (although harder metals require more effort to sharpen). It is possible to combine different materials, or different heat treatments, to produce desirable qualities in a blade. For example, the finest Japanese swords were routinely made of up to seven sections of metals and even poorer quality swords were often made of two. These would include soft irons that could absorb

1458-454: Is less desirable. This loss of material necessarily weakens the blade but serves to make the blade lighter without sacrificing stiffness. The same principle is applied in the manufacture of beams such as I-beams . Fullers are only of significant utility in swords. In most knives there is so little material removed by the fuller that it makes little difference to the weight of the blade and they are largely cosmetic. Typically blades are made from

1512-418: Is particularly true of acute blades and those made of soft materials. Dulling usually occurs due to contact between the blade and a hard substance such as ceramic, stone, bone, glass, or metal. The more acute the blade, the more easily it will dull. As the blade near the edge is thinner, there is little material to remove before the edge is worn away to a thicker section. Thin edges can also roll over when force

1566-440: Is poorly suited for working stone. Bronze is superior in this regard, and was taken up by later civilizations. Both bronze and copper can be work hardened by hitting the metal with a hammer. With technological advancement in smelting, iron came to be used in the manufacturing of blades. Steel , a range of alloys made from iron, has become the metal of choice for the modern age. Various alloys of steel can be made which offer

1620-648: The adversary. Severing a major blood vessel typically leads to death due to exsanguination . Blades may be used to scrape, moving the blade sideways across a surface, as in an ink eraser , rather than along or through a surface. For construction equipment such as a grader , the ground-working implement is also referred to as the blade, typically with a replaceable cutting edge. A simple blade intended for cutting has two faces that meet at an edge. Ideally, this edge would have no roundness but in practice, all edges can be seen to be rounded to some degree under magnification either optically or with an electron microscope. Force

1674-562: The ages into metal forms like copper , bronze , and iron , and culminating in modern versions made from steel or ceramics . Serving as one of humanity's oldest tools, blades continue to have wide-ranging applications, including in combat, cooking , and various other everyday and specialized tasks. Blades function by concentrating force at the cutting edge. Design variations, such as serrated edges found on bread knives and saws , serve to enhance this force concentration, adapting blades for specific functions and materials. Blades thus hold

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1728-428: The ballistic knife was originally designed as an offensive weapon and given current prosecutorial directives, it may be difficult to establish "reasonable excuse" for carrying such a knife before a UK prosecutor or court, especially as the carrying of a knife in public for self-defence is not acceptable as a "reasonable excuse". In the eyes of the law, claims of self-protection are presently viewed as an admission that

1782-414: The blade across the opponent's body and back. For straight-edged weapons, many recorded techniques feature cleaving cuts, which deliver the power out to a point, striking directly in at the target's body, done to split flesh and bone rather than slice it. That being said, there also exist many historical slicing techniques for straight-edged weapons. Hacking cuts can be followed by a drawing action to maximize

1836-420: The blade against an opponent even while close to the opponent where a straight sword would be more difficult to pull in the same fashion. The curved edge of an axe means that only a small length of the edge will initially strike the tree, concentrating force as does a thinner edge, whereas a straight edge could potentially land with the full length of its edge against a flat section of the tree. A splitting maul has

1890-500: The blade of a ballistic knife may also be propelled by an explosive charge, such as a blank pistol cartridge. The first press reports of what became known as the ballistic knife appeared in the late 1970s in connection with the Soviet Union's special operations forces. In his book Inside The Aquarium , Viktor Suvorov described a ballistic knife as part of a Soviet spetsnaz trooper's equipment. An NRS-2 combination knife/gun

1944-541: The blade. Soft-cored blades are more resistant to fracturing on impact. Folding pocket knives often have a groove cut in the side of the blade near the spine. This is called a nail pull and allows the fingernail to be inserted to swing the blade out of the holder. Some of the most common shapes are listed below. The sharp edges of a sword may be either curved or straight. Curved blades tend to glide more easily through soft materials, making these weapons more ideal for slicing. Techniques for such weapons feature drawing

1998-399: The bronze, stating that the blade was deposited as an offering to the storm-god by king Tuthaliya . Blade inscriptions become particularly popular in the 12th century knightly sword , based on the earlier, 9th to 11th century, the tradition of the so-called Ulfberht swords . Ballistic knife A ballistic knife is a knife with a detachable blade that can be ejected to

2052-441: The cut's effectiveness. For more information see Western Martial Arts or kenjutsu . Some weapons are made with only a single leading edge, such as the sabre or dusack . The dusack has a 'false edge' near the tip, which only extends down a portion of the blade's backside. Other weapons have a blade that is entirely dull except for a sharpened point, like the épée or foil , which prefer thrusts over cuts. A blade cannot perform

2106-762: The definition of a prohibited knife. Whilst "ballistic knives" are not specifically mentioned in any legislation, the marketing, sale, transfer, or possession in a public place of a ballistic knife could be construed to be illegal under the Restriction of Offensive Weapons Act 1959, the Knives Act 1997, the Criminal Justice Act 1988, and the Prevention of Crime Act 1953 . The Restriction of Offensive Weapons Act 1959 imposes criminal penalties for anyone who manufactures, sells or hires, or offers for sale or hire, or lends or gives to any other person "any knife which has

2160-427: The energy of impact without fracturing but which would bend and poorly retain an edge, and hard steels more liable to shatter on impact but which retained an edge well. The combination provided a sword that would resist impact while remaining sharp, even though the edge could chip if abused. Pattern welding involved forging together twisted bars of soft (bendable) low carbon and hard (brittle) higher carbon iron. This

2214-561: The example set by the federal law and passed even tighter restrictions, sometimes banning ownership of the knives outright within their state. Similar to conventional automatic knives , federal law makes ballistic knives with a spring-operated blade illegal to possess, manufacture, sell, or import "in or affecting interstate commerce." This means they are illegal to import from outside the United States, as well as buy or sell over state lines, including possessing or making them with intent to sell over state lines. The federal law also makes it

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2268-408: The fact they can cut food, they are still capable of inflicting injury. Plastic blades of designs other than disposable cutlery are prohibited or restricted in some jurisdictions as they are undetectable by metal detectors. Native copper was used to make blades by ancient civilizations due to its availability. Copper's comparative softness causes it to deform easily; it does not hold an edge well and

2322-579: The hero with the " echetlon ", or plowshare. This agriculture article is a stub . You can help Misplaced Pages by expanding it . This tool article is a stub . You can help Misplaced Pages by expanding it . Blade A blade is the sharp, cutting portion of a tool , weapon , or machine , specifically designed to puncture, chop, slice, or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are intended to cut. This includes early examples made from flaked stones like flint or obsidian , evolving through

2376-411: The intended use of the blade, the material it is to be made from, and any manufacturing processes (such as heat treatment in the case of steel blades that will affect a blade's hardness and toughness). A balance must be found between the sharpness and how well it can last. Methods that can circumvent this include differential hardening . This method yields an edge that can hold its sharpness as well as

2430-459: The knife is being carried as an "offensive weapon" without "lawful authority or reasonable excuse". 'Lawful authority' means those occasions where people from time to time are required to carry weapons as a matter of governmental duty, such as police officers or members of the armed forces, not private persons, hence the 'lawful authority' language cannot be relied upon to establish an exemption from prosecution of private individuals. Furthermore, as

2484-528: The marketing and sale of ballistic knives to civilians has been restricted or prohibited by law in several nations. In its spring-propelled form, the blade of a ballistic knife is theoretically capable of being fired to an effective range of around 5 meters (about 16 feet) at a speed of 63 km/h (39 mph). Ballistic knives using compressed air or gas propulsion to fire the blade can be made somewhat more powerful, and do not suffer from spring fatigue over time. In addition to spring, air, or gas propulsion,

2538-440: The material. This necessitates the blade being strong enough to resist breaking before the other material gives way. The angle at which the faces meet is important as a larger angle will make for a duller blade while making the edge stronger. A stronger edge is less likely to dull from fracture or have the edge roll out of shape. The shape of the blade is also important. A thicker blade will be heavier and stronger and stiffer than

2592-576: The other hand, the Book of Joel uses the phrase in reverse, "Beat your plowshares into swords". However, in classical antiquity during the Battle of Marathon , many Persians were slain by a deadly plowshare-wielding ally who appeared suddenly on the side of the ancient Athenians . After their victory and his disappearance, an oracle told the Athenians to worship the hero under the name Echetlaeus :

2646-531: The possession in any public place of an offensive weapon without "lawful authority or reasonable excuse." The term "offensive weapon" is defined under the Prevention of Crime Act 1953 as: "any article made or adapted for use to causing injury to the person, or intended by the person having it with him for such use". Under the Prevention of Crime Act, knives otherwise 'exempt' from penalty under the Criminal Justice Act 1988 when carried for "good reason or lawful authority" may still be deemed illegal if authorities conclude

2700-434: The sites of Chinese Majiabang culture dated to 3500 BC around Lake Tai . Plowshares have also been discovered at the nearby Liangzhu and Maqiao sites roughly dated to the same period. The British archaeologist David R. Harris says this indicates that more intensive cultivation in fixed, probably bunded, fields had developed by this time. According to Mu Yongkang and Song Zhaolin's classification and methods of use,

2754-442: The technique of differential hardening by covering their sword blades in different thicknesses of clay before quenching . Thinner clay allowed the heated metal to cool faster, particularly along the edge. Faster cooling resulted in a finer crystal structure, resulting in a blade with a hard edge but a more flexible body. European sword makers produced similar results using differential tempering . Blades dull with use and abuse. This

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2808-532: The triangular plow assumed many kinds and were the departure from the Hemudu and Luojiajiao spade, with the Songze small plow in mid-process. The post- Liangzhu plows used draft animals . Plowshares are often used in heraldry. The ancient phrase from the biblical Book of Isaiah , "to turn swords to ploughshares ," is still in common use today. These plowshares represent peaceful use of wartime capabilities. On

2862-656: Was designed and developed during the 1970s at the order of the Russian Ministry of Defence and KGB of the USSR . However, the NRS-2 was not in fact a ballistic knife, but a gun hybrid (instead of launching the blade, a small barrel aligned with the blade fires a non-standard 7.62mm bullet). Commercial versions of the ballistic knife first appeared in the US market in the mid-1980s. After hearing uncorroborated testimony from

2916-508: Was done because furnaces of the time were typically able to produce only one grade or the other, and neither was well suited for more than a very limited use blade. The ability of modern steelmakers to produce very high-quality steels of various compositions has largely relegated this technique to either historical recreations or to artistic works. Acid etching and polishing blades made of different grades of steel can be used to produce decorative or artistic effects. Japanese sword makers developed

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