The term COMMON FASTENER can be solved by two crossword solutions: SCREW (5 letters) and BUTTON (6 letters). A SCREW is a type of fastener consisting of a cylindrical shaft with a helical groove, or thread, that is used to join two objects together. It is one of the most common fasteners and is used in a wide variety of applications. A BUTTON is also a type of fastener, usually made of plastic or metal, which is used to secure two pieces of fabric together. Buttons are often used on clothing and accessories, and are available in a variety of shapes and sizes.