This is a heavy metal bar used as a small anvil in the episode Shockwave, part 2. While stuck in the decimated remains of the 31st century, Archer and Daniels work to find a way to get back to Enterprise. Eventually they try to make a primitive communications device from parts of a Starfleet communicator, tricorder and pieces of metal they find in the ruins. Daniels asks Archer to pound out some copper wire found wrapped around a wooden spoon; these wire pieces were "pounded out" by Archer using a "rock" and this metal piece.
