Torque wrench

Tool used to apply a specific torque

A torque wrench is a tool used to apply a specific torque to a fastener such as a nut, bolt, or lag screw. It is usually in the form of a socket wrench with an indicating scale, or an internal mechanism which will indicate (as by 'clicking', a specific movement of the tool handle in relation to the tool head) when a specified (adjustable) torque value has been reached during application. A torque wrench is used where the tightness of screws and bolts is a crucial parameter of assembly or adjustment.

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