A wrench was a tool used to increase torque and turn bolts, nuts or other hard-to-turn items.
Wrenches were used by the inhabitants of Miri's homeworld. In 2267, Jahn's friend used a wrench to bludgeon Captain Kirk. (TOS: "Miri")
Engineers aboard the USS Enterprise used wrenches in the late 23rd century. Ben Finney used a wrench found in the Enterprise engineering room as a weapon against Kirk. (TOS: "Court Martial")
In 2373, Crewman Amaro joked with Pechetti and Boq'ta – both engineers aboard Deep Space 9 – that he and Stolzoff would guard them while they "play[ed] with their wrenches." (DS9: "Empok Nor")
In 2268, when held captive on the surface of the planet Omega IV, Spock used a Kohm wrench-like tool in an attempt to repair a transmitter so they could be beamed up to the USS Enterprise. (TOS: "The Omega Glory")
Types of wrenches