Piece of hardware is a general term used to describe any type of physical object used in the construction or repair of a machine or structure. In this crossword, four different types of hardware are mentioned: SCREW (5 letters), NAIL (4 letters), BOLT (4 letters), and thumbscrew (10 letters). A SCREW is a type of fastener with a helical ridge that is used to hold two objects together. A NAIL is a thin metal spike with a flat head that is driven into wood or other materials to join them together. A BOLT is a type of fastener with a threaded shaft and a nut that is used to secure two objects together. A thumbscrew is a type of SCREW with a large head that can be tightened or loosened by hand.