Iron maidens were torture devices used in the Middle Ages.
The Tremas Master disguised his TARDIS as the band iron maiden while visiting 1215, (TV: The King's Demons) and again inside a museum exhibit in the 20th century. (PROSE: Tabby Cats And Time Lords)
Another TARDIS, this time owned by the Clocksmith, also disguised itself as an iron maiden. (AUDIO: The Eighth Piece, The Doomsday Chronometer)
When Merlin threatened to use an iron maiden on Rory Williams, Rory thought of the band, and said he preferred Oasis. (AUDIO: “The Once and Future Nurse”)