Roman door locks - more images 4 Some pull locks that were old-fashioned even in the Roman era were given a new design and became very widespread. They were inexpensive to manufacture and were fitted with a metal key. Sketch by the author. Metal pull lock. Metal key (with two hooks) and steel spring. Sketch by the author. Sketch 2: Metal pull lock, side view Reconstruction of a lavish bronze key with two iron hooks, intended for a metal pull lock. Sketch and photo by the author.