Pliers are for gripping and bending metal. They should never be used in place of a spanner for undoing nuts, as their serrated jaws can damage or round off a nut.
If you need to avoid marking the metal to be gripped, wind adhesive tape round the jaws of the 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 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 hand's grip 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.
Pincers are a similar tool with a different type of head used for cutting and pulling, rather than squeezing. Tools which are effectively pliers designed principally 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"; each type of connection uses its own dedicated tool.
There are many kinds of pliers made for various general and specific purposes.
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