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Pincers (tool)
Pincers are a hand tool used in many situations where a mechanical advantage is required to pinch, cut or pull an object. Pincers are first-class levers, but differ from pliers in that the concentration of force is either to a point, or to an edge perpendicular to the length of the tool. This allows pincers to be brought close to a surface, which is often required when working with nails. Pincers are primarily used for removing objects (typically nails) out of a material that they have been previously applied to. Carpenter's pincers are particularly suited to these tasks. If the pincers have perpendicular cutting edges, the pincers are often called end-nippers or end-cutters. Pincers, often red-hot, have also been used as an instrument of torture since ancient Roman times or earlier. Pliers are a similar tool with a different type of head used for squeezing, rather than cutting and pulling. See also * Chela (organ) * Pincer (biology) A pincer is the part of an arthropod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selection Of Pincers In A Mock-up Blacksmiths
Selection may refer to: Science * Selection (biology), also called natural selection, selection in evolution ** Sex selection, in genetics ** Mate selection, in mating ** Sexual selection in humans, in human sexuality ** Human mating strategies, in human sexuality * Social selection, within social groups * Selection (linguistics), the ability of predicates to determine the semantic content of their arguments * Selection in schools, the admission of students on the basis of selective criteria * Selection effect, a distortion of data arising from the way that the data are collected * A selection, or choice function, a function that selects an element from a set Religion * Divine selection, selection by God * Papal selection, selection by clergy Computing * Selection (user interface) ** X Window selection * Selection (genetic algorithm) * Selection (relational algebra) * Selection-based search, a search engine system in which the user invokes a search query using only th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand Tool
A hand tool is any tool that is powered by hand rather than a motor. Categories of hand tools include wrenches, pliers, cutters, files, striking tools, struck or hammered tools, screwdrivers, vises, clamps, snips, hacksaws, drills, and knives. Outdoor tools such as garden forks, pruning shears, and rakes are additional forms of hand tools. Portable power tools are not hand tools. History Hand tools have been used by humans since the Stone Age when stones were used for hammering and cutting. During the Bronze Age tools were made by casting the copper and tin alloys. Bronze tools were sharper and harder than those made of stone. During the Iron Age iron replaced bronze, and tools became even stronger and more durable. The Romans developed tools during this period which are similar to those being produced today. In the period since the industrial revolution, the manufacture of tools has transitioned from being craftsman made to being factory produced. A large collection of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Advantage
Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the ''law of the lever.'' Machine components designed to manage forces and movement in this way are called mechanisms. An ideal mechanism transmits power without adding to or subtracting from it. This means the ideal machine does not include a power source, is frictionless, and is constructed from rigid bodies that do not deflect or wear. The performance of a real system relative to this ideal is expressed in terms of efficiency factors that take into account departures from the ideal. Lever The lever is a movable bar that pivots on a fulcrum attached to or positioned on or across a fixed point. The lever operates by applying forces at different distances from the fulcrum, or pivot. The location of the fulcrum determines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutting
Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for wikt:cut, cutting are the knife and saw, or in medicine and science the scalpel and microtome. However, any sufficiently sharp object is capable of cutting if it has a hardness sufficiently larger than the object being cut, and if it is applied with sufficient force. Even liquids can be used to cut things when applied with sufficient force (see water jet cutter). Cutting is a compression (physical), compressive and shearing (physics), shearing phenomenon, and occurs only when the total stress (physics), stress generated by the cutting implement exceeds the ultimate Strength of materials, strength of the material of the object being cut. The simplest applicable equation is: \text = or \tau=\frac The stress generated by a cutting implement is directly proportional to the force with which it is applied, and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lever
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or ''fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is divided into three types. Also, leverage is mechanical advantage gained in a system. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever. As such, the lever is a mechanical advantage device, trading off force against movement. Etymology The word "lever" entered English around 1300 from Old French, in which the word was ''levier''. This sprang from the stem of the verb ''lever'', meaning "to raise". The verb, in turn, goes back to the Latin ''levare'', itself from the adjective ''levis'', meaning "light" (as in "not heavy"). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliers
Pliers are a hand tool used to hold objects firmly, possibly developed from tongs used to handle hot metal in Bronze Age Europe. They are also useful for bending and physically compressing a wide range of materials. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short ''jaws'' on one side of the fulcrum, and longer handles on the other side. This arrangement creates a mechanical advantage, allowing the force of the grip strength to be amplified and focused on an object with precision. The jaws can also be used to manipulate objects too small or unwieldy to be manipulated with the fingers. Diagonal pliers, also called side cutters, are a similarly-shaped tool used for cutting rather than holding, having a pair of stout blades, similar to scissors except that the cutting surfaces meet parallel to each other rather than overlapping. Ordinary (holding/squeezing) pliers may incorporate a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nail (fastener)
In woodworking and construction, a nail is a small object made of metal (or wood, called a tree nail or "trunnel") which is used as a fastener, as a peg to hang something, or sometimes as a decoration. Generally, nails have a sharp point on one end and a flattened head on the other, but headless nails are available. Nails are made in a great variety of forms for specialized purposes. The most common is a ''wire nail''. Other types of nails include '' pins'', ''tacks'', ''brads'', ''spikes'', and '' cleats.'' Nails are typically driven into the workpiece by a hammer or nail gun. A nail holds materials together by friction in the axial direction and shear strength laterally. The point of the nail is also sometimes bent over or ''clinched'' after driving to prevent pulling out. History The history of the nail is divided roughly into three distinct periods: * Hand-wrought (forged) nail (pre-history until 19th century) * Cut nail (roughly 1800 to 1914) * Wire nail (roughly 1860 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torture
Torture is the deliberate infliction of severe pain or suffering on a person for reasons such as punishment, extracting a confession, interrogation for information, or intimidating third parties. Some definitions are restricted to acts carried out by the state, but others include non-state organizations. Torture has been carried out since ancient times. In the eighteenth and nineteenth centuries, Western countries abolished the official use of torture in the judicial system, but torture continued to be used throughout the world. A variety of methods of torture are used, often in combination; the most common form of physical torture is beatings. Since the twentieth century, many torturers have preferred non-scarring or psychological methods to provide deniability. Torturers are enabled by organizations that facilitate and encourage their behavior. Most victims of torture are poor and marginalized people suspected of crimes, although torture against political prisoners or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Roman
In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 BC), Roman Republic (509–27 BC) and Roman Empire (27 BC–476 AD) until the fall of the western empire. Ancient Rome began as an Italic settlement, traditionally dated to 753 BC, beside the River Tiber in the Italian Peninsula. The settlement grew into the city and polity of Rome, and came to control its neighbours through a combination of treaties and military strength. It eventually dominated the Italian Peninsula, assimilated the Greek culture of southern Italy ( Magna Grecia) and the Etruscan culture and acquired an Empire that took in much of Europe and the lands and peoples surrounding the Mediterranean Sea. It was among the largest empires in the ancient world, with an estimated 50 to 90 million inhabitants, roughly 20% of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
