These are tools used to tighten hexagonal-shaped external and internal parts such as bolts and nuts. Common shapes include torque wrenches, adjustable wrenches, hex wrenches, ratchet wrenches, monkey wrenches, socket wrenches, and various other types. Their choice depends on the ease of use. The term originates from the English words “tighten” and “twist,” and there is a similar term “spanner.” “Spanner” and “wrench” are often used interchangeably and usually refer to the same tool.