Misplaced Pages

#737262

48-402: The rencong is slightly L-shaped and has a sharp blade with a slightly convex back. The blade can vary in length from 10 to 50 cm (3.9 to 19.7 in). The blade can be straight or cranked like a kris . It is held in a scabbard of wood , ivory , horn , or sometimes even silver or gold . The rencong is worn on one's belt around the waist. The design of a rencong depends largely on

96-463: A ripper , scarifier , or compactor . A blade forward of the front axle may also be added. For snowplowing and some dirt grading operations, a main blade extension can also be mounted. Capacities range from a blade width of 2.50 to 7.30 m (8 to 24  ft) and engines from 93–373 kW (125–500 hp ). Certain graders can operate multiple attachments, or be designed for specialized tasks like underground mining. In civil engineering "rough grading"

144-417: 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

192-469: 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

240-418: 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

288-404: 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

336-423: 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,

384-519: 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

432-414: 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

480-399: 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

528-547: 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

SECTION 10

#1732782667738

576-413: 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

624-408: 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

672-568: 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

720-543: Is a form of heavy equipment with a long blade used to create a flat surface during grading . Although the earliest models were towed behind horses, and later tractors , most modern graders are self-propelled and thus technically "motor graders". Typical graders have three axles , with the steering wheels in front, followed by the grading blade or mouldboard, then a cab and engine atop tandem rear axles. Some graders also have front-wheel drives for improved performance. Some graders have optional rear attachments, such as

768-576: Is a machine pulled by horses used for constructing canals and ditches in sandy soil. The design of the Fresno Scraper forms the basis of most modern earthmoving scrapers, having the ability to scrape and move a quantity of soil, and also to discharge it at a controlled depth, thus quadrupling the volume which could be handled manually. The Fresno scraper was invented in 1883 by James Porteous. Working with farmers in Fresno, California, he had recognised

816-418: 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

864-414: 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

912-461: 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

960-448: 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

1008-717: 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

SECTION 20

#1732782667738

1056-477: 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

1104-454: 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

1152-418: 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

1200-401: Is performed by heavy equipment such as wheel tractor-scrapers and bulldozers . Graders are used to "finish grade", with the angle, tilt (or pitch), and height of their blade capable of being adjusted to a high level of precision. Graders are commonly used in the construction and maintenance of dirt and gravel roads. In constructing paved roads , they prepare a wide flat base course for

1248-440: 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

1296-491: Is worn on the left side and drawn with the left foot forward. A quick step forward with the right foot adds momentum to the thrust. It is then whipped to the right with a snap of the hand, bringing the palm upwards while the elbow is close to the body. The thrusting arm is almost fully extended and the palm is turned downward just before piercing the target. While the thrust is the primary method of attack, circular and elliptical slashing techniques exist as well. The main targets are

1344-542: The martial arts is a stub . You can help Misplaced Pages by expanding it . This Indonesian history -related 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

1392-648: 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

1440-562: 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

1488-977: The angle and cant of the front wheels. Many models also allow frame articulation between the front and rear axles, which allows a smaller turning radius in addition to allowing the operator to adjust the articulation angle to aid in the efficiency of moving material. Other implement functions are typically hydraulically powered and can be directly controlled by levers , or by joystick inputs or electronic switches controlling electrohydraulic servo valves . Graders are also outfitted with modern digital grade control technologies, such as those manufactured by Topcon Positioning Systems, Inc. , Trimble Navigation , Leica Geosystems , or Mikrofyn. These may combine both laser and GPS guidance to establish precise grade control and (potentially) "stateless" construction. Manufacturers such as John Deere have also begun to integrate these technologies during construction. Early graders were drawn by humans and draft animals . The Fresno Scraper

Rencong - Misplaced Pages Continue

1536-414: 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

1584-420: 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

1632-541: 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

1680-402: 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 . Grader A grader , also commonly referred to as a road grader , motor grader , or simply blade ,

1728-441: 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

1776-637: The dependence of the Central San Joaquin Valley on irrigation, and the need for a more efficient means of constructing canals and ditches in the sandy soil. In perfecting the design of his machine, Porteous made several revisions on his own and also traded ideas with William Deidrick, Frank Dusy, and Abijah McCall, who invented and held patents on similar scrapers. The era of motorization by traction engines , steam tractors , motor trucks , and tractors saw such towed graders grow in size and productivity. The first self-propelled grader

1824-427: 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

1872-408: 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

1920-424: The final road surface . Graders are also used to set native soil or gravel foundation pads to finish grade before the construction of large buildings. Graders can produce canted surfaces for drainage or safety. They may be used to produce drainage ditches with shallow V-shaped cross-sections on either side of highways. Steering is performed via a steering wheel , or a joystick capable of controlling both

1968-683: The first rubber-tire self-propelled grader, the Caterpillar Auto Patrol, released in 1931. In addition to their use in road construction, graders may also be used to perform roughly equivalent work. In some locales such as Northern Europe , Canada , and places in the United States , graders are often used in municipal and residential snow removal . In scrubland and grassland areas of Australia and Africa , graders are often an essential piece of equipment on ranches , large farms , and plantations to make dirt tracks where

Rencong - Misplaced Pages Continue

2016-411: 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

2064-440: 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

2112-423: The social status of its owner. The most common type is made of brass or silver steel with a sheath of wood or buffalo horn. The rencong used by royalty is more ornate and less functional. Royal rencong have sheathes of ivory and blade made from gold, engraved with Quranic verses . Rencong technique is dependent on the weapon's size. Smaller lengths are favoured because they are more easily concealed. The rencong

2160-442: 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

2208-566: The throat, kidneys, groin, and abdomen. Aceh folklore ascribes mystical attributes and supernatural powers to the rencong. The form of the weapon is said to represent the Basmala . The rencong is today worn as part of traditional attire on ceremonial occasions. Aceh is also known as the "Land of the Rencong" ( Tanah Rencong ). This article relating to knives is a stub . You can help Misplaced Pages by expanding it . This article related to

2256-508: 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

2304-574: Was made in 1920 by the Russell Grader Manufacturing Company, which called it the Russell Motor Hi-Way Patrol. These early graders were created by adding the grader blade as an attachment to a generalist tractor unit. After purchasing the company in 1928, Caterpillar went on to truly integrate the tractor and grader into one design—at the same time replacing crawler tracks with wheels to yield

#737262