Tweezers are tools used for picking up and manipulating objects too small to be easily handled with the human hands. They are probably derived from tongs, pincers, or scissors-like pliers used to grab or hold hot objects since the dawn of recorded history. In a scientific or medical context they are normally referred to as forceps.
Tweezers make use of two third-class levers connected at one fixed end (the fulcrum point of each lever), with the pincers at the others.
Tweezers can be used for tasks such as plucking human hairs from the face or eyebrows, and whenever small objects have to be manipulated, including for example small, particularly surface-mount, electronic parts, and small mechanical parts for models and precision mechanisms. Stamp collectors use tweezers (stamp tongs) to handle postage stamps which, while large enough to pick up by hand, could be damaged by handling; the jaws of stamp tongs are smooth. One example of a specialised use is picking out flakes of gold in gold panning.It also used in kitchens to remove bones from fillets of fish a process known as pin boning.
Contents |
Tweezers are known to have been used in predynastic Egypt. There are drawings of Egyptian craftsmen holding hot pots over ovens with a double-bow shaped tool. Asiatic tweezers, consisting of two strips of metal brazed together, were commonly used in Mesopotamia and India from about 3000 B.C., perhaps for purposes such as catching lice.[1] There is evidence of Roman shipbuilders pulling nails out of construction with plier-type pincers.
Tweezers come in a variety of tip shapes and sizes. Blunt tip tweezers have a rounded end which can be used when a pointed object may get entangled, when manipulating cotton swabs, for example. Flat tip tweezers, pictured at right, have an angled tip which may be used for removing splinters. Some tweezers have a long needle-like tip which may be useful for reaching into small crevices. Triangular tip tweezers have larger, wider tips useful for gripping larger objects. Tweezers with curved tips also exist, sometimes called bent forceps. Microtweezers have an extremely small, pointed tip used for manipulating tiny electronic components and the like.
There are two common forms of construction for tweezers: two fused, angled pieces of metal, or one piece of metal bent in half. The bent tweezer is cheaper to manufacture, but gives weaker grip. The fused tweezer is more expensive, but allows for a stronger grip. The width between the tips of the tweezers when no force is applied also affects how powerfully they grip.
The original tweezers for mechanical gripping have given rise to a number of tools with similar action or purpose but not dependent upon mechanical pressure, including
Other uses of the same principle are named tweezers; although such terms are not necessarily widely used their meaning is clear to people in the relevant field. E.g., Raman tweezers, which combine Raman spectroscopy with optical tweezers.[3]