A blade is the flat part of a tool, weapon, or machine (such as a fan) that normally has a cutting edge and/or pointed end typically made of a flaking stone,such as flint, or metal, most recently steel. A knife is a handheld sharp-edged instrument consisting of handle attached to a Blade used for cutting A broader definition of a tool is an entity used to interface between two or more domains that facilitates more effective action of one domain upon the other A weapon is a Tool used either in Hunting, or attack or defence in Combat for the purpose of subduing enemy personnel or to destroy enemy weapons A machine is any device that uses Energy to perform some activity A mechanical fan is an electrically powered device used to produce an airflow for the purpose of creature comfort (particularly in the heat ventilation, exhaust Flint (or flintstone) is a hard sedimentary Cryptocrystalline form of the Mineral Quartz, categorized as a variety of Chert Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 A blade is intentionally used to cut, stab, slice, throw, thrust, position and/or place (an example of this is razor wire), shoot (an example of this is the ballistic knife) or strike an animate or inanimate object. Barbed tape or Razor Wire is a mesh of metal strips with sharp edges whose purpose is to prevent passage by humans A ballistic knife is a Knife with a detachable Blade that can be expelled from the handle/frame as a projectile by means of a spring-operated or gas-driven mechanism

Contents 1 Materials for production 2 Physics of blades 2.1 Geometry 2.2 Dulling 3 Patterns of knife blades 4 Patterns of sword blades 4.1 Decoration 4.1.1 Backsword 5 References

Materials for production

Material for weapon blades has to be carefully selected to achieve a balance between hardness and toughness and their ratio to each is dependent upon the intended use of a blade. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force Toughness, in Materials science and Metallurgy, is the resistance to Fracture of a material when stressed. In antiquity, the main metal used was copper, then of bronze and later iron. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Bronze is any of a broad range of Copper alloys, usually with Tin as the main additive but sometimes with other elements such as Phosphorus Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Perhaps the most well known is pattern welding, a technique used for katanas (samurai swords) and blades made to resemble damascus steel blades. Pattern welding is the practice in Sword and Knife making of forming a blade of several Metal pieces of differing composition that are forge-welded A is a type of Japanese sword ( nihontō) and often is called a "samurai sword is the term for the military nobility of Pre-industrial Japan. Damascus steel is a hot- forged Steel used in Middle Eastern Swordmaking from about 1100 to 1700 AD This was a very labor-intensive technique - and thus such swords were very expensive.

Various techniques may also be employed to make the blade stronger or harder. Copper and bronze can be "work-hardened" by simply hitting the blade with a hammer while it is cold. Work hardening, strain hardening, or cold work is the strengthening of a material by macroscopically speaking plastic deformation (which has the Blades made of steel with a high enough carbon content (greater than 0. Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 2%) can be heat-treated by heating the steel up to a critical point (most simple carbon alloys become non-magnetic slightly below that point), then quenching it with forced air, oil, or water depending on the steel. Second Album by Rock and roll Singer-songwriter near-legend Graham Parker. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. A quench refers to a rapid Cooling. In Polymer chemistry and Materials science, quenching is used to prevent low-temperature processes such as phase Quenching puts an enormous amount of stress on the metal, and often a sword would break into pieces during that step. If the sword survived heat-treating, it would be tempered by heating it to a relatively low temperature for an extended period of time. Tempering is a Heat treatment technique for metals and Alloys In Steels tempering is done to "toughen" the metal by transforming brittle The tempering process would make it slightly softer, but also tougher and "springier", and thus less likely to break or chip during everyday usage.

Case hardening is a process of increasing the carbon content at the surface of very low carbon steel. Case hardening or surface hardening is the process of hardening the surface of a metal often a low Carbon steel, by infusing elements into the material's Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 It is done by placing the object to be hardened in a sealed container along with carbon-containing material; in antiquity, this material was usually horn or hide. The container would then be heated until it was glowing red, and held at that temperature for a while, based on the size of the part being hardened, allowing carbon to penetrate the steel by a few thousandths of a centimeter. A centimetre ( American spelling: centimeter, symbol cm) is a unit of Length in the Metric system, equal to one hundredth At that point, the object would be dumped out of the container into a water bath to quench it, resulting in a very hard surface, but completely unhardened core. There is very little evidence of this having ever been done to swords except, perhaps, the very earliest of iron blades. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Due to the inherent weakness of a sword's cutting edge, coupled with the high-impact stresses of combat, such a thin hardened surface over a soft core would provide very little advantage in terms of edge-holding, other than mild wear resistance.

Another important aspect of many blades are so-called "fullers". Despite popular belief, fullers were not "blood grooves" that facilitated quicker bleeding of the victim and easier removal after insertion. fuller is a rounded or beveled groove on the flat side of a blade such as a Sword, Knife, or Bayonet (shown Rather fullers helped to make a blade stronger and more durable at the core by giving it an I beam cross section, thus reducing the amount of steel needed to keep the spine stiff. This was very important in ancient times when high quality steel was more labor intensive to make, smiths would scrape the fuller with a U shaped tool before hardening and reuse the scraps. Modern day fullers are made by positioning a heated blade over a bottom fuller, setting a like sized top fuller on the top side of the sword, and hitting the top fuller with a hammer. A hammer is a tool meant to deliver an impact to an object The most common uses are for driving nails fitting parts and breaking up objects

The most common materials used nowadays are various carbon and stainless steels, though strictly speaking anything that's fairly hard can be used. Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. In Metallurgy, stainless steel is defined as a Steel Alloy with a minimum of 11 This has led to exotic blade materials being used since history, such as obsidian, flint and bone. Obsidian is a naturally occurring Glass formed as an extrusive Igneous rock. Flint (or flintstone) is a hard sedimentary Cryptocrystalline form of the Mineral Quartz, categorized as a variety of Chert Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce Joining them in the modern day are more types such as synthetic sapphire,^[1] zirconium dioxide and even very hard plastics. Sapphire (antique greek hyacinthos refers to gem varieties of the mineral Corundum, an Aluminium oxide (Al2O3 when it is a color other than Zirconia redirects here For the Sailor Moon character see Dead Moon Circus. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products ^[2]

Physics of blades

The basic idea of a blade is very similar to a sharp point. The shape concentrates all the force onto a very small area, resulting in a high amount of pressure which allows it to penetrate matter. In Physics, a force is whatever can cause an object with Mass to Accelerate. Area is a Quantity expressing the two- Dimensional size of a defined part of a Surface, typically a region bounded by a closed Curve. Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface

A serrated blade (a blade which has many small "teeth") takes this further as each individual tooth concentrates the force on a smaller area which helps cut through more dense materials. A serrated knife can cut through objects solely with a sliding motion with little pushing force, this is useful for tools which require these attributes such as bread knives.

Some bladed weapons (and tools) have curved blades. A curve can serve two purposes, the first is that it allows for slicing by continuing to "push" on the surface as it is drawn across it. The other effect is to allow the force to be concentrated in an even smaller area.

As a rule the blade must be made of a substance which is harder than (or as hard as) the material it is intended to cut. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force If this isn't the case the blade will either be unable to cut (as it absorbs all the energy as it is damaged) or will wear away very quickly (if it is hard enough to transfer enough of the energy to damage the material). In practical terms the material must also be tough enough to last (e. Toughness, in Materials science and Metallurgy, is the resistance to Fracture of a material when stressed. g. glass is very hard but it shatters easily and thus isn't very effective as a material for a blade).

The problem is further compounded by the fact that heat treatments, which increase hardness for better edge-holding, inevitably reduce the material's toughness. Second Album by Rock and roll Singer-songwriter near-legend Graham Parker. Essentially speaking, a balance must be found between how well the edge must hold, and how well it can last. Methods that can circumvent this somewhat do exist however; for instance differential hardening allows for an edge that can hold well, and a body that can withstand mechanical stress. Differential hardening is a method used in Forging Swords and Knives to increase the hardness of the edge without making the whole blade Brittle Stress is a measure of the average amount of Force exerted per unit Area.

Geometry

An ideal blade would come to a perfect edge—not at all rounded—but that says nothing of the angle of that edge. The ideal angle is a function of the material being cut. For example, a tool bit for cutting metal may have nearly a 90° edge; it would probably not even be considered a blade. The term tool bit generally refers to a non-rotary cutting tool used in metal lathes, Shapers and planers. With very rigid materials such as metal, cutting deep into a piece with a blade would be impossible so deep cutting is done with a saw or grinder which provides kerf through which the cutting device can pass. A saw is a Tool that uses a hard blade or wire with an abrasive edge to cut through softer materials A saw is a Tool that uses a hard blade or wire with an abrasive edge to cut through softer materials With less-rigid materials such as a butternut squash, an acute blade prevents the blade from being pinched by the material. Butternut squash ( Cucurbita moschata) also known in Australia and Great Britain as Butternut pumpkin, is a type of winter squash. When cutting biomaterials such as tomatoes (which tend to have a low elastic modulus but high yield strain), the angle of the blade is less important since the material will bend, but the sharpness of the edge is important because if too much force is required, the material will be squashed rather than cut. An elastic modulus, or modulus of elasticity, is the mathematical description of an object or substance's tendency to be deformed elastically (i The yield strength or yield point of a Material is defined in Engineering and Materials science as the stress at which a material

Dulling

Blades dull with use and abuse. This is particularly true of acute blades and those made of soft materials. Dulling usually occurs due to contact between the blade and a harder substance such as a ceramic, stone or a tougher metal. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force The word ceramic is derived from the Greek word κεραμικός ( keramikos) To a first approximation, a harder material cannot be deformed by a softer material at their interface because the stress on both materials is the same at the interface and so the softer material will yield first. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force Stress is a measure of the average amount of Force exerted per unit Area. One exception to this is when the highest stress isn't at the contact point; this is why one can easily bend a steel paper clip even though an end of the same paper clip could scratch one's skin. Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 A paper clip (or sometimes paperclip) is a device which holds several sheets of Paper together by means of Pressure: it leaves the paper intact and

Patterns of knife blades

There are a variety of knife blade shapes; some of the most common are listed below.

(1) A normal blade has a curving edge, and flat back. A dull back lets the wielder use fingers to concentrate force; it also makes the knife heavy and strong for its size. The curve concentrates force on a small point, making cutting easier. This knife can chop as well as pick and slice.

(2) A curved, trailing-point knife has a back edge that curves upward. This lets a lightweight knife have a larger curve on its edge. Such a knife is optimized for slicing or slashing. Trailing point blades provide a larger cutting area, or belly, and are common on skinning knives.

(3) A clip-point blade is like a normal blade with the back "clipped" or concavely formed to make the tip thinner and sharper. The back edge of the clip may have a false edge that could be sharpened to make a second edge. The sharp tip is useful as a pick, or for cutting in tight places. If the false edge is sharpened it increases the knife's effectiveness in piercing. The Bowie knife has a clipped blade and clip-points are quite common on pocket knives and other folding knives. Bowie knife specifically refers to a style of knife popularized by Colonel James "Jim" Bowie and first made by James Black, although its common use refers

(4) A drop-point blade has a convex curve of the back towards the point. It handles much like the clip-point through with a stronger point less suitable for piercing. Swiss army pocket knives often have drop-points on their larger blades.

(5) A spear-point blade is a symmetrical blade with a spine that runs along the middle of the blade. The point is in line with the spine. Spear-points may be single-edged (with a false edge) or double-edged or may have only a portion of the second edge sharpened. Pen-knives are often single-edged, non-spined spear-points, usually quite small, named for their past use in sharpening quills for writing. Pen-knife may also nowadays refer to somewhat larger pockets knives which are often drop-points. Some throwing knives may have spear-points but without the spine, being only flat pieces of metal.

(6) A needle-point blade is a symmetrical, highly tapered, twin-edged blade often seen in fighting blades, such as the Fairbairn-Sykes commando knife. The Fairbairn-Sykes Fighting Knife is a double-edged stiletto with a foil grip developed by William Ewart Fairbairn and Eric Anthony Sykes in Its long, narrow point offers good penetration but is liable to breakage if abused. Although often referred to as a knife, this design may also be referred to as a stiletto or (slender variety of) dagger due to its use as a stabbing weapon albeit one very capable of slashing as well. A stiletto is a short Knife or Dagger, with a long slender blade of various designs A dagger (from Vulgar Latin: 'daca' - a Dacian Knife) is a typically double-edged blade used for Stabbing or thrusting

(7) A spay-point (once used for spaying animals) has a single, mostly straight edge that curves strongly upwards at the end to meet a short, dull, straight clip from the dull back. With the curved end of the blade being closer to perpendicular to the blade's axis than other knives and lacking a point, making penetration unlikely, spay points can be suitable for skinning.

(8) A Westernised tanto style knife has a somewhat chisel-like point that is thick towards the point (being close to the spine) and is thus quite strong. It is superficially similar to the points on most Japanese long and short swords (katana and wakizashi). A is a type of Japanese sword ( nihontō) and often is called a "samurai sword The (meaning "side arm" is a traditional Japanese sword with a Shōtō blade between 30 and 60 cm (12 and 24 inches with an average of 50 cm (20 inches The traditional Japanese tantō knife uses the blade geometry of (1). A is a common Japanese single or occasionally double edged Knife or Dagger with a blade length between 15 and 30 cm (6-12 inches The Westernised tanto is often straight but may also be gently curved. The point is actually a second edge on the end of the blade, with a total edge angle of 60 – 80 degrees. Some varieties may have the back edge angled to the point slightly and sharpened for a short distance from the point.

(9) A sheepsfoot knife has a straight edge and a straight dull back that curves towards the edge at the end. It gives the most control, because the dull back edge is made to be held by fingers. Sheepsfoot knives are good for whittling and trimming sheep's hooves.

(10) A Wharncliffe blade is similar in profile to a sheep's foot but the curve of the back edge starts closer to the handle and is more gradual. Its blade is much thicker than a knife of comparable size. [1]

(11 and 12) An ulu (Inuit woman's knife) knife is a sharpened segment of a circle. An ulu ( Inuktitut syllabics: ᐅᓗ, plural uluit) is an Inuit woman's all-purpose Knife. Inuit (plural the singular Inuk, means "man" or "person" is a general term for a group of culturally similar Indigenous peoples inhabiting This blade type has no point, and has a handle in the middle. It is good for scraping, and sometimes chopping. It is the strongest knife shape. The semi-circular version appears elsewhere in the world and is called a head knife. It is used in leatherworking both to scrape down leather (reducing thickness), and to make precise, rolling cuts for shapes other than straight lines. Leather is a material created through the Tanning of hides and Skins of Animals primarily Cattlehide The Tanning process

Not pictured is the undulating style found on items like the kris or flame-bladed sword. The kris or keris is a distinctive asymmetrical dagger indigenous to Indonesia, Malaysia, Brunei, Southern Thailand and A flame-bladed sword or wave-bladed sword has a characteristically undulating style of Blade. These blades have a distinct wavy design and are sharpened on both sides, typically tapering to (or close to) a symmetrical point.

Patterns of sword blades

Swords may have either a straight blade or a curved one. A straight sword was thought to primarily intended for hacking and stabbing, yet recent studies have shown this to be untrue, as many slicing techniques were used. The difference between a hacking cut and a slashing one is essentially the same as the difference between using a butcher's knife and a chef's knife; one forces an edge straight into a material while the other is pulled along the material to get more of a slicing action. A butcher is someone who prepares various Meats and other related goods for sale A chef is a person who cooks professionally In a professional kitchen setting the term is used only for the one person in charge of everyone else in the kitchen the executive Hacking cuts were usually followed by a slicing action, where the sword is drawn backwards to maximize the cut. For more information see Western Martial Arts or kenjutsu. Western Martial Arts (WMA refers to formalised fighting techniques and skills of European origin as distinct from those originating in Asia. is the Japanese martial art specializing in the use of the Japanese Sword ( Katana)

Some variations included

• the flame blade (undulated blade, for both psychological effect and some tactical advantage of using a non-standard blade: vibrations and easier parry)
• the colichemarde, essentially found in smallsword

Decoration

Decoration was often applied to the blade - usually engraving and sometimes inlaying with gold. A flame-bladed sword or wave-bladed sword has a characteristically undulating style of Blade. Colichemarde is a special type of Blade that was Forged and considered a member of the family of Small swords from the end of the 17th century to the beginning The small sword or smallsword (also court sword, fr épée de cour or dress sword) is a light one-handed Sword designed for thrusting Engraving is the practice of incising a design onto a hard usually flat surface by cutting grooves into it Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 In the 19th century, it became common to etch designs on the blade using acid and a wax template. The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are

Backsword

Single-edged swords have a back (hence their generic name of backsword). A backsword is a Sword having a Blade with only one edge The back of the sword is often the thickest part of the blade and acts to support and strengthen it This is the unsharpened edge.

Cavalry troops sometimes carried curved backswords. It was believed that a curved blade would impact in such a way as to be less likely to stick in the victim, and so be less likely to be pulled out of the rider's hand.

References

1. ^ English Russia >> Sapphire Knife
2. ^ Cold Steel Nightshade Series

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