A dowel pin is a cylindrical pin that is used to join two parts together in a mechanical assembly. It is typically made of metal or wood, and is often used in furniture or woodworking projects. While the term "dowel pin" is commonly used, there are several synonyms that can be used interchangeably, depending on the context. These include dowel, peg, rod, bar, shaft, and spindle. Each of these terms describes a cylindrical object that is used to connect two pieces of material, and can be used in place of "dowel pin" to add variety to language and avoid repetition in writing.