Are small tools used for picking up 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.
Women commonly use tweezers mainly for tasks such as plucking hair from the face or eyebrows, often using the term eyebrow tweezers. Other common uses for tweezers are as a tool to manipulate small objects, 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 specialized use is picking out flakes of gold in gold panning. Tweezers are also used in kitchens for food presentation to remove bones from fillets of fish in a process known as pin boning
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. Micro tweezers 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 tweezers is cheaper to manufacture, but gives weaker grip. The fused tweezers 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 powerful the grip is.
Classification by usage
in lead type
in dealing with stamps (see Philately)
in dealing with smaller coins (see Numismatics), to protect the coins these are wrapped at the tips with plastic
in the electronics
for hair removal (eyebrow tweezers)
in semiconductor technology in the form of wafer tweezers
in medicine (Forceps and Tissue Forceps)
in the household
In the textile industry as iron nubs
in science, laboratory
in aquatics at planting z. B. Aqua scraping
in watchmaker usage
There are also other tweezers, for example, so-called optical tweezers and vacuum tweezers to the tweezers.
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
Optical tweezers use light to manipulate microscopic objects as small as a single atom. The radiation pressure from a focused laser beam is able to trap small particles. In the biological sciences, these instruments have been used to apply forces in the Pico Newton range and to measure displacements in the nm range of objects ranging in size from 10 nm to over 100 mm.
Magnetic tweezers use magnetic forces to manipulate single molecules (such as DNA) via paramagnetic interactions. In practice it is an array of magnetic traps designed for manipulating individual biomolecules and measuring the ultra-small forces that affect their behavior.
Plastic tweezers used in first aid kit
Vacuum tweezers use differences in atmospheric pressure to grasp items from 100 micrometers in size up to parts weighing several pounds. Special vacuum tweezers tips are manufactured to handle a wide variety of items such as surface-mount electronics, optics, biological material, stamps and coins. They may be used to handle parts that are so small that conventional mechanical tweezers may cause parts to be damaged or dropped and lost.
Hot, or soldering, tweezers combine the squeezing action of mechanical tweezers with heating, to grip small surface-mount electronic devices while simultaneously heating them, for soldering or disordering.
Tweezers integrated with an electronic measuring device for evaluation of electrical parameters of small-size electronic components.
Carbon Nano-tweezers have been fabricated by deposition of MWNT bundles on isolated electrodes deposited on tempered glass micropipettes. Those nanotube bundles can be mechanically manipulated by electricity and can be used to manipulate and transfer micro- and Nano-structures. The nanotube bundles used for tweezers are about 50 nm in diameter and 2 µm in lengths. Under electric bias, two close sets of bundles are attracted and can be used as Nano scale tweezers.
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.