Fastenings is a general term for a type of mechanical parts used when two or more parts are fastened together into a whole, and are also called standard parts in the market. Fastenings usually include bolts, studs, screws, nuts, self-tapping screws, wood screws, washers, retaining rings, pins, rivets, assemblies and joints, welding nails and other parts. Today, we will briefly introduce several types of parts.
(1) Bolt: A type of Fastenings composed of two parts, a head and a screw, which need to be matched with a nut to fasten and connect two parts with through holes, and the connection is detachable.
(2) Stud: A type of Fastenings without a head but with threads at both ends. When connecting, one end is screwed into a part with an internal threaded hole, and the other end is passed through a part with a through hole, and the nut is tightened even if the two parts are tightly connected as a whole. This type of connection is called a stud connection. It is also a detachable connection. One of the parts mainly used for connection has a large thickness, a compact structure or is not suitable for bolt connection due to frequent disassembly.
(3) Nut: with internal threaded hole, the shape is generally flat hexagonal column, flat square column or flat cylinder, matching bolt, screw Zhuhai or steel structure screw, used to fasten and connect two parts to make it a whole .
(4) Screw: A type of Fastenings composed of two parts: head and screw. According to the purpose, it can be divided into three categories: steel structure screws, set screws and special purpose screws. The machine screw is mainly used for the fastening connection between a part with a tightly threaded hole and a part with a through hole, and no nut is required. Set screws are mainly used to fix the relative position between two parts, and special purpose screws are used as lifting parts.
(5) Welding nails: heterogeneous Fastenings composed of polished rods and nail heads or without nail heads, which are fixedly connected to parts or assemblies by welding, so that they can be connected with other parts.
(6) Assembly and connection pair: Assemblage refers to a kind of Fastenings supplied by combination, such as a combination of machine screws and flat washers; connection pair refers to a kind of Fastenings supplied by a special combination of bolts, nuts and washers , For example, high-strength large hexagon head bolts are used to connect steel structures.