Screws, nuts, nuts, nuts are standard parts, also known as fasteners
The outer thread is usually a bolt (common name screw)
The thread is a nut (common name nut) that is sleeved on the bolt.
Screws
The "screw" is just a general term for fasteners. It is used in everyday language. It includes: bolts, screws, nuts, as long as there are threaded fasteners.
bolt
A type of fastener consisting of two parts, the head and the screw (cylindrical with an external thread), which is required to cooperate with the nut and is used to fasten two parts with through holes. This type of connection is called a bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection.
Stud
Without the head, only a type of fastener with threads on both ends. When connected, one end must be screwed into the part with the internally threaded hole and the other end through the part with the through hole, and then screw on the nut even if the two parts are fastened together in one piece. This type of connection is called a stud connection and it is also a detachable connection. It is mainly used for occasions when one of the connected parts has a large thickness, requires a compact structure, or is frequently used for bolting because of frequent disassembly.
Screws
It is also a type of fastener composed of two parts of the head and the screw. It can be divided into three categories according to the purpose: machine screws, set screws and special purpose screws. The machine screw is mainly used for a part with a tight threaded hole, and a fastening connection with a part with a through hole, and does not require a nut to be fitted (this type of connection is called a screw connection and is also a detachable connection; it can also be Fits with a nut for fastening connections between two parts with through holes.) Set screws are used to fix the relative position between two parts. Special-purpose screws such as eyebolts are used for lifting parts.
Nuts
With internally threaded holes, the shape is generally flat hexagonal, cylindrical or flat cylindrical, with bolts, studs or machine screws, used to fasten and connect two parts, making it a piece overall.