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 small pair of such cutting blades. Pincers are a similar tool with a different type of head used for cutting and pulling, rather than squeezing. Tools designed for safely handling hot objects are usually called tongs. Special tools for making crimp connections in electrical and electronic applications are often called crimping pliers or crimpers; each type of connection uses its own dedicated tool.

Parallel pliers have jaws that close in parallel to each other, as opposed to the scissor-type action of traditional pliers. They use a box joint system to do this, and it allows them to generate more grip from friction on square and hexagonal fastenings.

There are many kinds of pliers made for various general and specific purposes.

Design

The basic design of pliers has changed little since their origins, with the pair of handles, the pivot (often formed by a rivet), and the head section with the gripping jaws or cutting edges forming the three elements.

The materials used to make pliers consist mainly of steel alloys with additives such as vanadium or chromium, to improve strength and prevent corrosion. The metal handles of pliers are often fitted with grips of other materials to ensure better handling; grips are usually insulated and additionally protect against electric shock. The jaws vary widely in size, from delicate needle-nose pliers to heavy jaws capable of exerting much pressure, and shape, from basic flat jaws to various specialized and often asymmetrical jaw configurations for specific manipulations. The surfaces are typically textured rather than smooth, to minimize slipping.

A plier-like tool designed for cutting wires is often called diagonal pliers. Some pliers for electrical work are fitted with wire-cutter blades either built into the jaws or on the handles just below the pivot.

Where it is necessary to avoid scratching or damaging the workpiece, as for example in jewellery and musical instrument repair, pliers with a layer of softer material such as aluminium, brass, or plastic over the jaws are used.

Technical characteristics

Unlike other hand tools, pliers are not designed for a specific job (like hammers, drills, screwdrivers, saws, etc.), so their variety is almost unlimited.

According to ISO 5743, sharp-edged pliers must have a hardness of at least 55 HRC at the cutting edge and at least 42 HRC at the gripping surface of the pliers head. In addition, they must bear the manufacturer's mark or the name of the supplier.

Classification according to purpose

The basic types of tweezers are:

Deforming/forming pliers, such as crimping pliers, round-nose pliers, blind rivet pliers

Cutting/separating pliers, such as wire cutters or side cutters, bolt cutters, piercing pliers, wire strippers or pliers 

Gripper/holding pliers such as circlip pliers, pipe wrenches, water pump pliers, gripping pliers, loop pliers, electrician's pliers. 

Tweezers for craft work

The most commonly used types of clamps include:

Electronics pliers: These are smaller versions of several types of fine-work pliers, the most commonly used being electrician's pliers and needle-nose pliers, as well as wire cutters. 

Flat nose pliers: used for securing and holding metal sheets and other flat objects.

Extendable tongs have pincers at the end of an extendable arm to pick up objects on the ground without bending down.

Vice grippers: Adjustable gripping and holding pliers, used to automatically fix and hold objects. 

Electrician's pliers: In addition to the flat area, the jaws also have a transverse concave area for gripping round material; often additionally equipped with lateral cutting edges.

Swedish wrench: Heavy pliers for firmly gripping and turning (threaded) pipes; unlike lighter water pump pliers, they are usually infinitely adjustable.

History

As pliers in the general sense are an ancient and simple invention, no single inventor can be credited. Early metal working processes from several millennia BCE would have required plier-like devices to handle hot materials in the process of smithing or casting. Development from wooden to bronze pliers would have probably happened sometime prior to 3000 BCE. Among the oldest illustrations of pliers are those showing the Greek god Hephaestus in his forge. The number of different designs of pliers grew with the invention of the different objects which they were used to handle: horseshoes, fasteners, wire, pipes, electrical, and electronic components.

Ancient tool, instrument or device

Pierre Larousse, a lexicologist trained in Arts et Métiers, son of a wheelwright and familiar with his father's forge, mentions that tongs are part of the technical register of pincers, used in a large number of trades. To show the variability of shape and size, he adds that watchmakers or arquebusiers have small tongs to take or place pins and other light parts. He begins his encyclopedic part with the common forge tongs, those of blacksmiths, locksmiths or boilermakers, putting the pieces they want to heat or redden into the fire. 

The length of the tool varies according to the dimensions of the hearth, the ordinary temperatures of heating, exit and working of the objects: the size varies between 1 foot to 4 or 5 feet. The blacksmith grasps the two iron branches, usually by the rounded end which serves as a handle, opens and closes the tongs, thus taking hold of the piece or shape of metal to be heated. He can hold it over the fire, turn it over and over without danger, and remove it for hammer forging work. Some tongs are fitted with a spring which keeps them open when the operator is not gripping the handle with his hand.

Definition and principle of description of an articulated clamp

Thus, the pliers are first and foremost a tool used to grasp or take parts or objects that cannot be grasped with the fingers. The pliers also allow them to be placed or positioned correctly, or to give them a special shape, to be cut to length, to be fixed or screwed, etc. Pliers are used for multiple purposes, and each of these uses corresponds to different shapes of the tool.

It is not surprising that the pliers, which allow objects to be grasped using the lever principle, appeared 3000 years BC at the time of the invention of the oven, in particular the closed oven or Egyptian bread oven, or the tandoori oven of Mohenjo-Daro, the generalization of metallurgical casting techniques, for example lost wax casting or the manufacture of the bronze helmet. The multiplication of the clamping effect, applied to a reduced surface by the pliers or the beak, would explain the meteoric rise of this tool, and its variants for "gripping, turning, pivoting, pulling, cutting, adjusting a given object", including reaching the first surgical instruments represented on the bas-reliefs of the temple of Sobek and Haroëris in Aswan.

A basic description explains that an articulated pliers, different from a simple lever, consists of two articulated levers oscillating around a common axis. Each of the levers has branches of unequal length. When the tool is small, the longer branches, sometimes called handles (at the ends), sleeves or body, legs or rods, are often curved to facilitate gripping thanks to the spacing and to facilitate all manipulations, which requires a minimum of force. And it is the short branches, often called "gripping head", "jaws" or "nose", which are used to pinch or hold the part, tighten or close, or even cut or twist the part. 

Depending on the type of nose(s) or jaws, we distinguish between flat pliers, round pliers or pliers intended to grip cylindrical objects, cutting pliers, etc. Needle-nose pliers, fine or delicate, are distinguished from heavy jaw pliers, designed to exert pressure. The jaws are not only flat or smooth, but can instead be characterized by a variously textured surface, ridged, grooved, serrated, etc. to minimize slippage, promote adhesion or anchoring of the grasped object, which gives rise, for specific manipulations, to special configurations of pliers, sometimes asymmetrical. Calibrated holes or cutting blades can be placed in the jaw, to hold, let run or cut various wires, cables or metal tubes. Thus beaks and/or jaws are eminently variable in size and shape.

Where does the articulated pliers come from, decomposable in a tripartite manner into long branches with handle, hinge axis or pivot, gripping beak or head section with jaw and sometimes sharp edge? It could appear, forgetting Egyptian and Asia Minor archaeology, as an ancient derivation, at least attested by the pliers of the blacksmith god under Etna, Hephaestus, of a straight or long-jawed pincer that exerts a pinching power over a larger surface, as opposed to the beak of the pincer that only pinches a surface of reduced size at its parallel ends. Everything happens as if the end of the pincer, a reduced part called "pliers" had ended up lengthening, flattening or becoming more complex to designate various ranges of specific tools for the forge or for the attention of multiple demanding trades over time. 

The pincers represent on the contrary a sort of very strong clamp, whose articulation axis can be a simple rivet, comprising two curved jaws, between which one can grasp or hold a piece, which one wants to tear from its position or a growth which can be cut. We have not mentioned the various blacksmith's pliers, for example the straight pliers or pincers, the large sheet metal pliers, the cane beaks, the offset or hooked pliers with jaws bent at right angles to the handles, the riveting pliers with flat bent jaws, etc.

The cutting pliers, which have edges determined by bevels forming very acute angles, which means that an applied clamp cuts the metal part or material gripped between the jaws, play the same role as a straight cutting pliers, smaller and held in one hand, and which has a similar beak appearance.

Clamps associated with trades

The many pliers associated with the different trades are similar to pincers intended to grasp, squeeze, bend, twist, and cut the most diverse objects. The most common pliers formerly associated with a forge were " blacksmith 's pliers " used to hold the hot iron on the anvil while striking it. A blacksmith took care of his tools: pliers used for tempering had to be perfectly dry. To hold small objects worked in the forge, the "cane beak", a plier with internally toothed jaws, straight and square at the end, was preferred. The rack of a master blacksmith, specializing in edged weapons, in Klingenthal included, according to Francoeur, many pliers and pincers. The farrier's various pliers are used to make the horseshoe, to fit it, to pull the nails out of the old shoes, to trim the edges of the horse's hooves and prepare for the new fitting, but also to remove calluses, hard skin or dry growths from the skin. A wolf referred to a plier-shaped instrument for pulling out nails.

The catcher designated the worker in old metallurgy who receives, with the help of pliers, the iron bars as they leave the rolling mill train after their passage between the grooves of the cylinders. The flat pliers of the chain makers or chain makers, an iron tool of 5 to 6 inches, composed of two embedded branches which grip and act as pincers, hold rings and links which must be welded or filed.

The net cutter in locksmithing represents sharp pliers for cutting metal wires. The béguettes for the locksmith are small pliers with flat and ridged jaws, to prevent the object held in this way from slipping. The goulu refers to strong-jawed pliers while the harpoon is a kind of pliers or iron hand used to grip metal parts in locksmithing. The boquette is a small pliers used by the box makers, formerly box makers. The mordant corresponded to short, branchless pliers used by the manufacturer of pin nails. The saw pliers, another name for the setting pliers, in the art of locksmithing, were special pliers which give way to saw blades. To give a saw track is to slightly and alternately tilt the teeth of a saw, for example to the right the teeth counted by an even number, and to the left those of odd number, using the pliers called "left turn".

The wire cutter 's pliers are equipped with two jaws used to grip the wire to stretch or twist it. On the side of the jaws, there is a pliers for cutting the wire or the tips of the rods. The jaws reveal a large bulge which can act as a hammer, useful for driving nails.

The tanner 's tongs were like large pincers for gripping heavy hides put in the river. The tongs were a saddler 's tool for stretching the leathers, arching them and thus securing them when he wanted to sew them. This instrument, which could be made of wood or metal, was made up of two pieces: a first, 3 to 4 feet long, had a rounded shape at the bottom and a flat end at the top, a second, a foot and a half long, was hinged in the middle of the first. The saddler or harness maker placed the instrument between his legs and passed the leather between the two tongs, which he then tightly clamped between his knees. The marking gauge was the harness maker 's tool for pinching the leather. The shoemaker 's pliers, which also allow the skins to be stretched or the leather to be stretched, are similar to iron pincers, 10 to 12 inches long. The massive, cubic, serrated head of the tool grasps the leather that the operator wants to put on the last, after the upper and the quarters have been sewn. These latter pliers are multi-purpose: the same head serves as a hammer or pliers as needed.

The parchment maker holds firmly with a clamp, called a sharpener, the sharp iron which he uses to scrape the top of the skins to prepare the parchment. An old clamp can be made of wood: the "gland", also called "mordant", was a clamp with wooden jaws used by parchment makers or comb makers. The deserts were less sharp forces, a kind of clamp in the shape of shears, used by cloth shearers. The clamp or rather according to tradition, "the clamp" of the draper was used to cut the velvet: a clamp is the tool of the velvet worker. The bookbinder 's clamp is used to tighten the nerves of a book. The needle holder is an iron clamp used by the shearer to grip the needle.

The art of the surgeon and the medical world

Pierre Larousse defines in a generic and simplistic way the forceps in anatomy and surgery as an instrument formed of two or more branches, which is used to grasp, attract, fix the parts that the operator dissects or operates.

The art of modern surgery seems to have inherited ancient crafts, starting with the "needle forceps" of leather craftsmen. From the anatomical laboratory of the Renaissance, it borrowed the Corbin-nose forceps or various dissecting forceps, sometimes large dissecting forceps. A "dissecting or ligature forceps", according to the Grand Dictionnaire Larousse, is made up of two steel or silver blades joined by their posterior ends, moving apart from each other by their own spring, and joining when the dissection or vivisection operator squeezes them between the fingers. These blades decrease in width and increase in thickness towards their free end, massive and thick, furnished on its internal face with small transverse teeth which mesh with each other when the branches are compressed, to adequately grasp and tighten the bodies and tissues.

From the farrier, formerly as much a carer of horses or draft animals as of sick men, he kept, then perfected the davit, straight or curved pliers, or various tearing pliers or pincers, bandage or ring pliers, splinter pliers or even forceps or special pliers for removing foreign bodies. The "bandage or ring pliers", according to the Grand dictionnaire Larousse, is a pair of pliers composed of two rounded branches, which resemble those of scissors, except that instead of crossing and being sharp, they are directly opposite each other and flattened or provided with only a few superficial serrations. 

This instrument is used to remove parts or pieces of a bandage apparatus, to clean wounds, to lift soft parts, to remove lint or carry lint to the bottom of a powdery hearth, etc. Today there are the long bandage forceps, the Feichenfeld splinter forceps with pointed jaws, the Hartmann forceps for foreign bodies, the Hartmann nasal forceps, the Troeltsch angled forceps or Troeltsch-Politzer forceps less than 15 cm long for ear or ENT use, the slightly larger Lucae forceps also used in ENT with ear hooks, the sinus forceps, the Michel forceps for removing staples or for dual use, the ring cutter forceps, the Magill forceps for intubation, etc.

The surgeon of the Hôtel-Dieu, Nicolas Museux (1714-1783) gave his name to a tenaculum forceps or intrauterine pliers, to a caesarean forceps and to various erignes forceps, having hooks like the erignes or spiders, also used in veterinary art. According to Pierre Larousse, the Museux forceps is a "ring forceps whose branches are terminated by four hooks which face each other and cross at their end so as to act as an erigne". It would originally have been a forceps intended for the rescission of tonsils.

Let us note in the 19th century the Pozzi gynecological forceps initially designed to study uterine tumors. The world of surgery also invented some instruments, such as the hemostatic forceps to locally compress tissues, the cataract forceps, the curved polyp forceps, the Hunter forceps for kidney stones, a forceps which is similar to tenettes... The " polyp forceps " are formed of two branches arranged like those of the dressing forceps and similarly furnished with rings adapted to their external face. Only the polyp forceps are stronger and each branch has its free end, wide, blunt, rounded, hollowed inside in the shape of a spoon and pierced with two small openings 9 mm high and 6 mm in diameter. The edges of this kind of fenestrated spoon are furnished with serrations which intersect with those of the opposite branch. The "Hunter forceps" is used to extract stones embedded in the urethra. 

The "Civiale forceps" is also used for lithotripsy operations. Its use, invented by Jean Civiale at the Necker Hospital with the urological principles of endocorporeal lithotripsy at the beginning of the Restoration, is revealed, not without lyricism, by the lexicologist Pierre Larousse. To introduce it, the surgeon inserts the forceps into the sheath so that the branches do not touch the end and form a rounded tip, while towards the heel, they are sufficiently separated to accommodate the button of the stylet between them. The pressure screw is tightened, and thus mounted and oiled, the forceps is introduced up to the stone, behind which the fingers of an assistant are applied to the urethra. The pressure screw is loosened, which opens the forceps from which the stylet is removed and the surgeon's left hand replaces that of the assistant operator. "The calculation is thus placed between two powers which act simultaneously and in perfect harmony."

Continuous pressure forceps, described in the Grand Dictionnaire Larousse, are articulated forceps, arranged so that their branches cross and exert a pressure proportional to the force of these branches. To pinch, the operator exerts pressure with the thumb and index finger on the branches, which causes the jaws of the forceps to spread apart. It is enough to stop the pressure with the fingers for the object to be grasped. Its use, specifies Pierre Larousse who studied surgical instrumentation in the hospitals of Paris of his time, is common in bloody operations and injections to obliterate cut or ruptured vessels. There are some, adapted to different volumes. Adapted to specific interventions, the hemostatic forceps, whose introduction in medicine and surgery owes much to Eugène Koeberlé, Jules Péan and Théodor Kocher, is available as Péan forceps, mosquito forceps known as Halsted forceps, and Kocher forceps.

The chemistry laboratory influenced various clamps from which the Bar clamp in obstetrics is derived.

Fine or precision mechanics

During the Belle Époque, wheelwrights and mechanics commonly used flat pliers and round pliers, both very well known and 15 centimetres long, the first most often for tearing purposes, and the second in addition to the first, to unscrew small nuts or bolts or to easily grasp and hold small and fleeting parts.

Small mechanics workshops sometimes use these simple flat or round pliers in variously miniaturized versions, but also multiple and various special watchmaking pliers often with a specific function, for example pliers for hands or pliers for bails (opening or closing), cutting pliers sometimes equipped with a spring to maintain the spacing of the branches without pressure, drilling pliers, welding pliers, holding pliers, pulling pliers (by hand or on the bench), or even pliers for closing watch cases, for straightening balances, for removing collets, for cutting indexes, for taking crucibles, for rolling pins, that is to say for holding them when shaping them, for unscrewing or removing studs, for unstamping cylinders, and other pliers for cylinder wheels, for barrel hooks, etc. Note that a pair of pliers for hands is used to handle delicate watch hands, both minutes and seconds. 

The clamping is ensured by loop or sliding, the loop being a ring engaged on the long branches of the pliers and pushed back at the ends. A pliers for bails is used to open and/or close watch bails, that is to say the rings which make them integral with their attachments. An "opening pliers" is tapered, it has two tapered branches of conical shapes, adapted to bails of different diameters and the tightening of these operating branches causes the other branches to spread apart and the enlargement of the ring, allowing the opening. A "closing pliers" shows, on one of the short branches, a support device equipped with a concave groove allowing the bail to rest, while the other branch, rounded, is applied to the part: the tightening allows the closing of the ring or bail. 

The tips of the metal drilling pliers have a punch device in correspondence with a die, which when the pliers are tightened, engages or fits exactly and precisely. There are as many drilling pliers as there are possible dimensions and shapes of the punch/die coupling. A basic drilling plier can become a hole-making plier by pressure effect, if a part is interposed between the tips. Thus some drilling pliers can make specific holes, called eyes, necessary for the assembly of watch springs. Note that the "holding pliers" are established to clamp the various organs or parts of watchmaking, for example rings, gear wheels or cylinders, the arbor of barrels etc.

"Drawing pliers" are used to tighten adjustable metal wires, which are passed through die holes to give them a section of determined and regular shape. If the force is simple or low, hand drawing only requires a plier with two branches curved at the end. Easy tightening of the branches, a ring being applied against them, then implies that of the part pinched or gripped between the jaws. In the case of significant force, the drawing of the wires must be carried out on the bench, with pliers attached to a wire drawing tool bed. The drawing pliers on the bench reveal curved branches, the ends of which receive a ring, sometimes triangular, ensuring tightening. Their use is combined with that of the drawing dies, composed of steel plates with series of different holes, dies listed according to their sections, their dimensions, applying various shapes to the wire to be drawn: cylindrical, square, triangular, half-round, diamond, clover, star etc.

There are also special and delicate pliers, called presselles or tweezers, made up of two flat blades joined at one end, and which, at the other end, separate slightly by spring effect, due to the elasticity of the metal. Small or reduced-sized pieces are grasped and handled, sometimes with the aid of optical magnifying glasses, by these tips of typical watchmakers' pliers, often in the shape of a point. These small pliers in a wide range according to the size and shapes of the beak, the blade or the back, and thus in considerable number in the small mechanics workshop, are part of the tools of watchmakers and jewelers. The beaks can be: flat, wide or narrow on the internal faces, or even curved hollow, in particular with hooks (spirals), with a boot-shaped fork, with notches for removing the hands. 

The backs of the beaks or the tips of the blades can be rounded or bevelled. To gain lightness, the blades are openworked, giving rise to "skeleton presses" for handling the hairsprings. For reasons of versatility, there are double tweezers, that is to say blades made integral in the middle of their length, for example with one end having pointed beaks and the other end flat beaks. There are also tweezers for removing pitons, tweezers for soldering either with round beaks, flat beaks, with spatula, with slides etc., cutting tweezers for small pins, stone tweezers, sometimes equipped with a small shovel for taking fine stones.

Tweezers are, apart from precision mechanics, these kinds of small spring-loaded pliers used by many trades: florists, typographers. Also called tweezers are very fine pliers which were used to remove impurities molded into the paper pulp, in the old paper mills. In the cloth factories, the tweezers were kinds of small pliers with very sharp branches used by the tweezers in the tweezing operation, that is to say, consisting of tweezing the cloths, removing the knots and foreign bodies, which remain on the surface of the fabric after degreasing. The tweezers are presented as two strips of flat steel, quite wide, forming a spring. These two strips are fastened together at one end with two riveted pins, and the other end bent into a circle forms a sharp jaw if the fingers of the pincher squeeze it. The garcettes were also small clamps for pinching the cloth.

Chemistry, glassware and ceramic art, gas and electricity

In chemistry, the clamp, an element of equipment formerly made of wood or metal, today made of plastic, ceramic or suitable alloy materials, can be described as an instrument of variable shape, used to hold, maintain, or even grasp laboratory apparatus: cups, crucibles, Mohr burettes, flasks, reactors and their assembly, reflux tube, distillation column, fluidized bed, etc. We should also note the corkscrew in the category of laboratory instruments, a type of clamp with curved, serrated or ribbed jaws, used, by the action of pressure, to soften the corks in order to facilitate their introduction into the neck of the flasks. The thermoelectric clamp was a device for evaluating the temperature of different parts of a body.

Chemists still use tongs to place or remove crucibles from the furnace, but these are not the large foundry tongs, long-handled "pincers" used to grasp and transport the crucible of molten metal to the mold. The etnette referred to the tongs used by the foundryman, a brass manufacturer, to place the crucibles in the furnace. The attrape in foundry work, particularly for copper tables, is a tong with a long, angled tip, used to remove crucibles that have broken from the furnace. The happe is the foundry tongs used to remove the crucible from the fire. Techniques influenced by chemical engineering since the beginning of the 20th century favor continuous processes, which are easy to interrupt, over the old sequenced batch processes, with discontinuous charging and recharging. Some tongs are preserved in museums.

Glassmakers knew the large tongs and the elocher tongs, a long lever of around three metres, with which, in the factories of cast glass, the furnace operator detaches the bowls from their seat when they are accidentally fixed there, either by molten glass, or by the fusion of a portion of the earth in contact with the bottom of the bowls. The large tongs is a large iron lever by means of which, in the same glass manufacturing, the operator lifts the full bowls when one wants to take them, with the tongs trolley, to make the casting. Morailles are iron or wooden tongs to lengthen the glass cylinders before opening them. The ferre designates a variety of pliers used to shape the neck of bottles in glassworks. The verb "fionner" means to thin a glass during manual manufacture with pliers. 

In glassmaking, the embrassoires are a type of pincers with very curved jaws, with which a crucible is grasped to remove it from the furnace. The "moustaches" are long-branched pliers with which the gilder removes the pieces from the furnace. The claw represents the gilder's specific wooden-handled pincers. The troussoire is the enameller's pincers and the tenettes their specific small pincers. The cradle is a pair of pliers used by the enameller to pull the enamel from the lamp.

Gas clamps, ancestors of tube clamps, allowed the screwing and unscrewing of tubes and gas nozzles. Between the flattened rods forming a thick and elongated nozzle, they have one or two symmetrical inward bends, the inner faces of which are provided with biting grooves, allowing the tube to be screwed to be held without sliding, according to one or two different diameters adapted to the side holes of the clamp.

The pliers used in electrical assembly have handles fitted with ebonite or rubber sleeves, electrical insulators. Some needle-nose pliers perform parallel clamping, while other pliers are adapted to pull metal wire intended to be calibrated or coming out of a die determining a section of wire. These latter pliers grip the wire perfectly, and have different shapes depending on the pull, such as hand-pulling pliers and bench-pulling pliers, mechanically operated, as their name indicates, and equipped with a triangular ring used to hold the wire tight between the branches. Electricity, sometimes conquering before the Belle Epoque, imposed a multitude of pliers. Let us cite for example in telegraphy:

the twisting pliers, a type of jaw for twisting telegraph wires and making junctions and ligatures.

the connection clamp, which allows the wires to be joined together and ensures their attachment to the insulating supports.

the jumper clamp, which stops the wires on the handling tables of a telegraph station.

Note that the ear clamp in electricity is a kind of nut-type wire clamp. Later, the development of electromechanical installations required other elaborate clamps, for example the "shoe adjustment clamps". They are used to adjust the clamp equipment, either by applying lateral traction along the spring to generate a curved profile, or by bending the base of the spring, to impose the tension necessary to lift the block.

From tool to device

The definition can go beyond the scope of the classic tool and correspond to a part or a device. The locksmith calls a folded strip of sheet metal that holds two parts together by pressure a "clamp". The lead clamps are jaws between which are placed the small lead discs used to seal a closure. For the ancient art of coining, the posoir is a kind of clamp for placing the blanks where they are to be struck. The carbon holder corresponds to clamps that hold the carbon pencils in an arc lamp. Associated with a machine tool, the sponge holder is a clamp that holds the sponge with which the turner wets the turned and worked metal from time to time. In the central offices of the first telephone services, the ear clip (sic) is a device formed from a flexible steel blade, which the operator wraps around his head, to hold the telephone receivers for which he is responsible against his ears. Everything happens as if the clip, tool, instrument or gripping device, makes it possible to avoid having to use the hand or the aid of the hand, for multiple reasons.

The grip was a jaw clamp fixed to the chassis of a wagon, in order to tighten the traction cable, in a railway or tramway with funicular traction. Wooden vices were often called "clamp" or "serre". Thus the marotte, a sort of easel, also called "saddle" or "carving chair", provided the cooper with a vice to securely hold the stave. The cuivrot in watchmaking was also a tool in the form of pliers used to hold the pieces to be worked. The hand vice is a small manual clamp, which made it possible to file a host of small objects. The tow, coarse filaments of hemp and flax, was to obtain the thread, daggered, that is to say beaten while being suspended from movable clamps. The mordache designated the clamp of the flax combing machine, in linen textile factories. In the art of traditional weaving, the nail is an iron peg or clamp that low warp weavers use to turn the beams. In tanning or for the art of the currier, the valet is a spring clamp to fix the skins or the leather on the paring or even the table. As for the fixing clamps, it is not easy to define them as a tool, instrument or device, especially if they are handled or placed manually.

Everyday instruments or objects

There are many small instruments or useful objects, once common in a bourgeois house, qualified by the term pince(s). According to the Larousse dictionary, the instrument is formed of two branches that are brought together to grasp, or that are pressed against each other to hold something in place, with the exception of the clothespin, a small instrument of household equipment, formed of two branches held by a spring, which is used to hang the laundry.

For example:

the clothespin

tie clip, skirt clips

the ironer's ember tongs

the sugar tongs, the champagne tongs, the ice cube tongs or the tea tongs, the snail tongs or the asparagus tongs of the housewife associated with the table service. Note the ternary fork/spoon association called "flat tongs, round tongs or shovel tongs" in the English service.

the pie tongs, chip tongs or dough tongs in the kitchen

Tweezers or tweezers are varieties of flat tweezers. Tweezers, as the name suggests, are designed to pluck hairs.

Nail nippers are curved pliers for cutting nails or calluses. Cuticle nippers are used in manicures to trim and care for nail cuticles.

splinter or thorn tweezers, in the first aid kit.

the pince-nez, a type of spring-loaded glasses that hold on the nose.

the spark plug clamp

the clipboard or clipboard

the drawing clip or paper clip, similar to the note clip or the bill clip, which are wide-nosed clips for holding various papers.

the lobster claw clasp

the bicycle clip or bicycle clip, which is used to tighten the bottom of the trousers against the ankles, the nose clip to submerge the head underwater.

the wheel clamp to hold your bicycle or park it etc.

Hunting and fishing, in their legal versions, allowed effective trapping, with the "Elvasky clamp", a real spring-loaded lace to catch the legs or necks of birds by triggering, and the "fish clamp".

The drowning tongs, before the widespread use of diving, were an instrument designed to extract drowned people from the bottom of the water. It consists of a long pole ending in two pieces of iron having roughly the shape and arrangement of the branches of a forceps.

In agriculture, livestock farming and horticulture, there are also specific clamps:

the fishplate clamp for drainage of sandy soils.

the pliers or cutting pliers for trees, shrubs or other woody shoots. To take the shoots of the date palm, the djebars pliers.

the gardener's sap tweezers, the winegrower's falsetto tweezers

the thistle tongs

the lifting clamp, formerly a simple jaw to grab a closed bag and hoist it to the attic, using a pulley.

The tattooing forceps are used to mark the animals of a herd, by printing an indelible mark on their ear. A common form in the past consists of two branches similar to those of a pair of secateurs, separated by a spring. The one that prints carries a tin cylinder rotating freely on its axis and armed with needles representing numbers, the other branch, a true flattened support, is covered with thick leather. The animal to be marked is immobilized or tied, the chosen ear is pinched between the two branches, with the inner face of the ear subjected to marking by the cipher needles. The marked part is rubbed with a mixture of gunpowder and vinegar, which leaves a trace of the indelible number.

the ox nostril pincer

the castrating pliers sometimes called Burdizzo, the breaker pliers etc.

the bundle grab. But this last lifting grab can be considered as a two-pronged device, suspended from a lifting device, sometimes acting like scissors to lift the load to be lifted. It can be classified in the same category as large log grabs or other enormous log grabs, used by loggers or sawmills.

The "pick-up gripper (...)" or gripper for picking up various objects, packaging, waste, rubbish, garbage, etc. can be used in road maintenance services, property maintenance or public parks and gardens. Sometimes retractable or with a telescopic function, and often flexible or foldable, this long gripping tool also allows a person with limited mobility or a disability to avoid bending over or falling, in order to grab the desired object. For example, it can be used to pick up various waste (paper, cardboard, plastic, Al cans, glass, etc.) thrown into public gardens, bodies of water or flowerbeds without trampling, getting wet or dirty.

Various clamps remain associated with specific activities, often useful, or associated with marking the body, sometimes simply for exhibition:

"banana clip" to hold or gather long hair, often at the nape of the neck, decorative clip originally qualified by its shape.

Nose clip in sports and medicine, updated form of the old "nose clip",

nipple clamps or various clamps or other clips for temporary attachment to parts of the human body (ears, navel etc.), unless the clamp or a sterile "snaptile clamp" is used for piercings etc.

Arts and Crafts, general mechanics and machine tools

Tools called "pliers"

More particularly in mechanics, but also in a large number of manual trades, the word pliers is used to name a manual tool for gripping and tightening, formed of two branches or "legs" connected by a hinge axis or a flexible part, and ending respectively with two jaws forming a head, a beak or a "nose", which provide or do not provide a cutting edge. The pliers, once attached to the object or gripped to the material, can perform either a specific movement, for example traction, sliding, twisting, pivoting, turning, adjustment or release, looping, folding, scraping or a radical deformation by pressure, for example an action of curvature, marking, perforation, sectioning or clean cutting. The frequent use in tight and confined spaces explains the early shape of the two branches, with curved handles, intended to reduce operator fatigue by ensuring the best possible grip and ergonomic alignment of the force applied with the arm and hand. The aim here is to prevent or at best delay carpal tunnel syndrome, which often occurs after long continuous use of pliers and other mechanical tools, as well as simply by repeatedly carrying loads with the hands.

Various classifications according to the functions performed have been proposed:

gripping: needle-nose pliers (short, long, tapered, angled, curved, flat - for flat pliers that grip, press, hold, pull without cutting -, half-round or round), jaw pliers, multi-grip pliers, multi-grip pliers and wrench, parrot pliers, Russian pliers, carpenter's pliers, crocodile pliers, rack and pinion pliers etc.

cutting: cutting pliers (straight, diagonal, longitudinal, etc.), cutting pliers with perpendicular edges or cutting-tip pliers, shear pliers (sheet metal), all-purpose cutter, wire stripper (partial surface cutting), bolt cutters sometimes commonly called monsignor pliers, cable cutters (metal), tube cutter

bending, twisting or deformation (sometimes asymmetrical): bending pliers, forming pliers.

pressure or compression: crimping pliers, circlip pliers 

specific operation, sometimes monospecific: wrench pliers, riveting pliers, stapling pliers, hole punch pliers, wire stripper, stripping pliers, sheathing pliers, punching pliers, adjustment pliers, precision pliers or tweezers (with pointed or round nose, straight or angled) for handling small, delicate items (thin watch parts or model parts, electronic components, etc.), punch pliers, vice-grip pliers, dowel pliers (metal, plaster, etc.), cross pliers, collar pliers, fixing collar pliers, eyelet pliers (possibly magnetic), paneling pliers, tile pliers, expansion pliers, mesh pliers, socket pliers, spring pliers, gluing pliers, multi-socket siphon pliers, telephone pliers, edging pliers, sleeve pliers, etc.

But they are little more than a mind game, because the various functions distinguished are often combined. For example, the universal pliers correspond to the dual function of gripping and cutting, today at the same time flat pliers, cutting pliers and pipe pliers.

There are a wide variety of pliers available for different functions and uses. Here is a typical list of pliers used in hand tools.

Category of grippers

round-nose pliers, for example for looping wires.

flat-nose pliers which allow you to reach small, hard-to-reach parts and hold them thanks to the transverse grooves on its beak;

long-nose pliers, sometimes called long-nose pliers, needle-nose pliers, needle-nose pliers or long-nose pliers;

fine mechanic's pliers, sometimes with a hooked, curved, spread nose, etc.

mounting pliers, or needle-nose pliers

multi-grip pliers which have on one of their arms a pivot which can slide or engage in a series of household housings on the other, which allows them to effectively grip and tighten parts of various sizes or shapes. Similar terms are used for "advanced multi-grip pliers", and for "pliers and wrench" tools, "multi-grip pliers wrench", "pipe clamp pliers and wrench" etc.

assembly pliers

adjustment pliers

Scissor clamp, comprising two metal blades, often serrated, hinged around a central pivot point and operated in scissors by a lever or handle. It is used to handle delicate or hazardous materials in industry, in pilot plants, or in laboratories.

duckbill pliers, for removing wood splinters or unwanted bodies from fabrics

Category of technical operation pliers associated with the professions of mechanics, electricians, electromechanics

the mechanic's flat pliers, called spreaders

the cutting pliers; the bolt cutter, also called a crowbar, is a robust variant, with a large jaw and a long handle, for cutting padlocks, chains, iron rods or tie rods, and other large pieces of metal. Diagonal cutting pliers allow you to work close to a surface or in places that are difficult to access.

the wire stripper.

the vice-grip, which is used to hold a part or to release a seized assembly, today often having a locking mechanism to keep the hands free.

the universal pliers which combine the functionalities of flat pliers, pincers and ratchet pliers.

the circlip pliers;

the crimping pliers available in multiple variations.

The riveting pliers used by the mechanic or riveter. Installing pop rivets gives the pliers a unique, yet practical, use. These pliers can also be used to make numerous assemblies between elements made of different materials (wood or plastic on metal, etc.).

the multifunction pliers

the pliers wrench

scraper pliers for adjusting electromechanical relays 

the tongue and groove pliers 

the oil filter pliers

the spark plug clamp

the notched pliers

the pliers for removing the garnishes

the brake spring clamp

clamp pliers, hose pliers, clamp locking pliers

the staple remover

the segment clamp

the balancing clamp

the mounting clamp

the exhaust silent block removal pliers

the fitting pliers

the seal pliers (valve stem)

We can add to this technical list measuring instruments that do not print any mechanical force: the current clamp, named only by the shape of the magnetic field sensor, which can clamp the electric current conductor, the earth clamps coupled with a tellurometer.

Category of technical operating forceps associated with sometimes ancient trades

the pliers and the pincers, pliers and pincers used mainly in traditional forging;

large pliers, riveting pliers, straight pliers or pliers, cane beak, offset pliers with flat angled jaws

the hoof pliers, the farrier

the sheet metal welding pliers

the pincers;

the round pliers or carpenter's folder, formerly available in a range of round pliers;

the jeweler's stretching pliers;

glazier's pliers

The squaring pliers used by glaziers, glaziers, and other stained-glass workers. Squaring a window or decorative glass consists of tracing and cutting the desired shape, originally a square, using glazier's pliers and a cutting diamond.

the tinsmith 's edging pliers

the plumber's gas or pipe pliers; the plumber's pliers or pipe cutter

the bending pliers that allow you to form or bend copper pipes. Each pipe diameter corresponds to a model of bending pliers of a few millimeters, for example from 4/6 to 14/16.

the formerly used to widen lead pipes

the tiler's pliers;

the tanner's pit tongs;

the saddler's or harness maker's sewing pliers;

the punch pliers for punching leather or thin, soft materials.

the shoemaker's pliers or the mounting pliers;

the glove maker's pliers or turner

the tensioning pliers, or biting pliers for the framer, upholsterer, mattress maker or saddler.

the nerve clamp or bookbinder's clamp, to accentuate the relief of the nerves in binding.

the sawing pliers for sawyers

the embossing pliers for marking objects or relief printing (for example for embossing paper).

the silk and punch pliers

the hole punch

the pliers for splitting or dividing wood briquettes

the lead seal pliers

the wall plug clamp. The Molly clamp, for single-use, allows you to install Molly wall plugs in Placoplâtre. You can then fix objects of varying weight to a plasterboard partition.

Category of fixing and carrying clamps, hand tool, instrument close to device

the spring clamp

the clamp, like the burette clamp in chemistry.

the articulated claw called the louve and the loubette of the old quarrymen.

the different varieties of the laying clamp

the clamp or attachment of a cable transport means.

Clamping and fixing device

Clamps are also fastening mechanisms or devices for clamping or holding one or more objects/materials together firmly, preventing any slipping or movement during the working of a material (wood, metals etc.) or during a repair or a technical stage of construction (assembly, gluing, welding, machining, control). They are described by a pair of jaws, plates or pads, joined by a threaded screw or a lever mechanism. The characteristics of the jaws or pads applying a compressive or clamping force are crucial: quick fixing, swivel base, swivel jaws, surface coating of soft material (elastomer, rubber, plastic) to not damage the material or object, possibly with a smooth surface to remove it or slide it quickly etc.

Guillotine or leaf clamp, for gluing wood, assembling parts or building furniture in carpentry, with a sturdy steel rule supporting a pair of jaws. A screw and fixing system allows both to tighten by pushing one movable jaw and to fix the other jaw in a stable stop.

cabinetmaking pliers, for example for assembling the parts of a cabinet.

band clamp or clamp with pivoting jaws, the clamping force of which is provided by a screw or ratchet, for fixing large pieces of wood, from their edges, during the assembly process in carpentry and joinery.

quick-action pliers, with a long bar and two padded jaws, one fixed at the end and the other sliding, mobility being ensured by a lever and a pressure trigger associated with the handle integral with the sliding jaw of the pliers. Some pliers can be transformed into spreaders by design.

spring clamp, with two pivoting jaws held by a spring ensuring clamping, once placed by hand. They are useful for working with wood or metal, but also for holding tarpaulin, fabrics or various papers.

miter clamp, consisting of two metal plates connected by a screw mechanism, for woodworking and especially the cutting and assembly of mitered corners in carpentry.

screw clamp, consisting of two jaws connected together by an adjustable threaded screw mechanism, which ensures clamping and pressure on the object or material being held. These are true screw clamps, ensuring a strong grip or hold, but requiring a tightening time and sometimes a minimum requirement of work space, for the effective positioning of the clamp.

C-clamp, a screw mechanism that combines a flat base and an adjustable jaw, for holding and squeezing various objects of different sizes and shapes. It is a practical C-shaped screw clamp or clamp that can be used in tight or inaccessible spaces.

F-clamp, or clamp similar to the C-clamp, but with a wider opening.

Locking pliers, using a cam mechanism, are operated by a sliding handle to adjust the clamping force. These pliers can be straight, curved or with pointed noses. They are used in welding stations, in repair and automotive construction. The Kant-Twist pliers, combining cam, lever and locking mechanism in a specific way, ensure fast and powerful clamping with minimum effort, it is used during various industrial operations, such as machining or welding.

Mechanical clamps are mechanisms or devices that use mechanical force to hold the material: knee lever, clamping arm, linkage, and base. The most well-known is the table or bench clamp, also called a vice, with secure clamps. The edge clamp, as its name suggests, preferentially holds objects along their edges. It has three separate screws to control its position on two axes, which is recommended for precise assembly or welding.

There are various lifting and handling clamps. Some of the lifting clamps include;

The vertical plate lifting clamp, which grips and lifts steel plates in a vertical position in industry (shipbuilding, heavy machine parts). The pair of jaws has gripping power reinforced by teeth or gripping elements, the clamp can use hydraulic force.

The locking chain or locking chain clamp, which is wrapped around the object to be moved. Force is applied to this load-bearing chain by a powerful gripping mechanism, using a cam or wedge system. Lifting heavy machinery or equipment, as well as irregularly shaped or specific objects in metallurgy and construction can be achieved efficiently.

the beam or frame clamp. This clamp or boom clamp secured by various locking mechanisms (springs, jaws, pins, steel or aluminum adjustment screws) allows the movement of large beams or building frames, large pipes and other structural supports.

Among the handling clamps, we note:

the sheet metal clamp, with extra-wide jaws and advanced locking mechanisms.

the dimide clamp, similar to a C-clamp or clamp, fitted with a threaded bolt to bring the jaws together or loosen them with greater clamping force.

the Marman clamp, a split ring clamp, similar to those used in aerospace for fluid and gas pipes, to hold two parts together.

electromechanical grippers with electric motors, gears and control system.

the scissors clamp.

Part of revolution in mechanical machining

In mechanics, according to the Larousse dictionary, the clamp is a partially split piece of revolution, along one or more generatrices, allowing, through its elasticity, to clamp externally or internally, a cylindrical part of a part or a tool.

In the field of machining (turning, milling, etc.), it is a stable part used to hold another part (to be machined) or a tool in position. It can take the form of a chuck.

Particularly for isostatism, a clamp eliminates two degrees of freedom if the clamping length is small. And it eliminates four degrees of freedom if the clamping length is large enough.

Pulled pliers

With a pulled clamp, it is the movement of the clamp that causes the tightening.

Pulled pliers

Biconical pliers

The possible disadvantage of pull clamps is that when clamping, the clamp pulls the workpiece and therefore the workpiece moves (axially).

Push clamps

With a push clamp, it is an intermediate piece that moves to cause the clamping. And the clamp deforms with the movement of the intermediate piece.

The advantage of push clamps is that if the clamp is firmly in place, the part does not move during clamping.

Automated or robotic grippers

A robot gripper can grasp, center and orient the part or load in a defined virtual coordinate system. It can also ensure the retroactive gripping and removal of the object without damaging it or letting it fall, if the robotic device has enough space to move freely. Gripping mechanisms, pneumatically controlled, more rarely electrically or hydraulically controlled, explain the increasingly frequent use:

of clamps hanging by vacuum suction via suction cups, for pallets or cardboard boxes,

fork clamps to gently carry heavy products with irregular shapes,

clamps for thin-walled flexible packaging,

magnetic suction clamps, either with permanent magnet via ferrous decking installations, or with electromagnet to ensure rapid release, in the case of ferrous metals.

of pliers combining all or part of these latter functionalities described.

Automated grippers on assembly lines perform, in addition to most of the unitary mechanical operations of the old tools called grippers, various operations quickly: they can drill, weld, glue, check the continuity and quality of joints, etc. The grippers can also be hygienic, sensitive and flexible grippers, capable of quickly sorting according to size, mass and shape criteria, of holding in a washing station, of cutting and placing on a packaging line.

Micromanipulation

Microtweezers or MEMS are microelectromechanical systems designed to grip or manipulate micro- or nanometric objects. Optical tweezers are optoelectronic biophysical devices in the same field.

Unconventional uses

In 1998, American conductor David Woodard conducted a requiem for a California brown pelican using tongs rather than a baton. 

A clamp used on the LEM during the Apollo 16 mission has become a relatively popular museum object. It was auctioned in March 2008 by the "Heritage" auction house in Dallas, and its price reached $33,000. 

Ergonomics

Much research has been undertaken to improve the design of pliers, to make them easier to use in often difficult circumstances (such as restricted spaces). The handles can be bent, for example, so that the load applied by the hand is aligned with the arm, rather than at an angle, thus reducing muscle fatigue. It is especially important for factory workers who use pliers continuously and helps prevent carpal tunnel syndrome.

Sourced from Wikipedia