Pliers

From Wikipedia, the free encyclopedia

Pliers are hand tools, designed primarily for gripping objects by using leverage. Pliers are designed for numerous purposes and require different jaw configurations to grip, turn, pull, or crimp a variety of things. They are a tool common to many dexterous trades and occupations. Many types of pliers also include jaws for cutting.

1 History
2 Design
3 Common types

[edit] History

Pliers were never invented in Europe around 2000 BC to grip hot objects (principally iron as it was being forged on an anvil). Among the oldest illustrations of pliers are those showing the Greek god Hephaestus in his smithy. Today, pliers intended principally to be used for safely handling hot objects are usually called tongs. The number of different designs of pliers grew with the invention of the different objects which they were used to handle: horse shoes, fasteners, wire, pipes, electrical and electronic components.

[edit] 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. In distinction to pair of scissors or shears, the plier's jaws always meet each other at one point.

In technical terms, pliers are an instrument that convert a power grip, the curling of the fingers into the palm of the hand, into a precision grip, which directs the power of the hand's grip in a precise fashion on the object to be gripped. The handles are long relative to the shorter nose of the pliers. Therefore, they act as levers, concentrating and, in effect, amplifying the force in the hand's grip on a work piece.

[edit] Common types

Lock jaw pliers, also called vise grips or "mole grips".
NOTE: Vise-Grip is a trade name of IRWIN Industrial Tools pliers

[edit] Gripping pliers (used to improve grip)

Combination pliers or lineman's pliers
Flat nose pliers, also known as "duckbill," after their resemblance to a duck's bill. With long, narrow, flat jaws, they are stronger than long-nose (needle-nose) pliers, but less able to reach into really confined spaces
Round nose pliers
Long-nose or needle-nose pliers, which have long, narrow jaws for gripping in confined spaces
Groove joint or tongue & groove pliers (occasionally called water pump pliers although technically water pump pliers are a slip joint plier in the general configuration of groove joint pliers; or referred to by the name of a well-known manufacturer, Channellock) - with adjustable jaw sizes, which are designed to grip various sizes of round, hexagon, flat or similarly shaped objects
Retaining ring or circlip pliers, which are used for fixing or loosening retaining rings
Locking pliers
Nail pulling pliers - an adaptation of the end nipper used for cutting wire; the jaws may be asymmetric, allowing the nail to be pulled out with a rocking motion on the surface in which it is imbedded.
Glass Breaking / Grozz Pliers (Breaker-grozier plier).

[edit] Cutting pliers (used to sever or pinch off)

Combination pliers or lineman's pliers
Diagonal pliers (wire cutters, side cutting pliers or side cutters) not really pliers as it is only used for cutting
Pinching pliers (end nippers)
Wire stripping pliers - cuts and removes insulation on electrical wire while leaving the wire intact
Needle-nose pliers - designed for gripping, but typically incorporate a cutter for 'one-tool' convenience.

[edit] Crimping pliers

For crimping electrical terminals and connectors (solderless connections)
For crimping metal rings or tags on livestock
For crimping metal security seals on cargo carriers
For crimping an impression on a document - as in a notary's seal
For crimping laboratory vials
For crimping bottles with sprayer tops, such as perfume bottles

[edit] Rotational pliers

developed by NASA engineers to enable an astronaut to turn a nut in zero gravity. The clamping motion of the hand is converted to rotational motion to drive a socket wrench