Screwdriver

A screwdriver was a tool. After an infostamp left him believing he was the Doctor, Jackson Lake carried such a tool, calling it his "sonic screwdriver". (TV: The Next Doctor)

It could also be used as a weapon. Miss Quill told Charlie to stab a screwdriver through the hand of Orla'ath - a guise of the Lankin. (TV: Nightvisiting)