If we classify the fasteners for its intended purpose, then their most important characteristic is the type of compounds in which the parting parts of the detachable connection and the parts of the non -disintegrated connection is used. The first type includes the following products: screws, nuts, washers, bolts, screws, studs. The second type includes rivets, various parts for soldering, anchor, dowel, as well as special details that are designed to glue the surface. All these products can have a massive purpose, they can be high -strength elements with specially chopped thread, it can be designed for hermetic compounds, for supporting structures, as well as for structures, with a large load. In addition, fasteners are widely used when connecting polymeric materials, as well as various composite materials. Due to this, they are used in construction and industry and act as the main fasteners (bolts, shurs, screws, anchor, nuts).
