Fasten Metal can be accomplished by using a RIVET, which is a five letter word. A RIVET is a mechanical fastener that is used to join two or more pieces of metal together. It is inserted into a hole in one piece of metal and then a second piece of metal is placed over the RIVET and it is then hammered or pressed down to create a secure connection. Rivets are commonly used in the construction of aircraft, ships, and other large structures.