Hammer

A hammer was a tool.

Dominic Montfalcon lost control of his pyrokinesis after hitting his thumb with a hammer and burned himself to death. His wife Clarissa, who had the ability to reset time, caused the event to unhappen and saved his life. (PROSE: The Death of Art)

Donna Noble used a hammer to knock out a Sontaran by striking his probic vent. (TV: The Poison Sky)

Fenric possessed a medallion in the form of a hammer that could conjure up time storms. (AUDIO: Gods and Monsters)

discovered that TARDIS control consoles were not hammer-proof, and used a hammer to wreck the Seventh Doctor's TARDIS Time and Space slide controls to prevent him from altering the course that he'd set for the ship. (PROSE: How did this creep get in here, Professor?) Following the Last Great Time War, the Ninth and Tenth Doctors kept a hammer in their TARDIS control room to make the TARDIS behave. (TV: Rose - The End of Time)

Donna Noble used the Doctor's hammer as a weapon against the Tenth Sontaran Battle Fleet after being transmatted onto their flagship, striking it against their probic vents. (TV: The Poison Sky) During his farewell tour, the Tenth Doctor saved Martha Jones and Mickey Smith from a Sontaran sniper by copying Donna's example. (TV: The End of Time)