1、First, screws: Actually. The standard saying is without screws. Screws are commonly known as "screws" with external threads, which are a wide range of concepts.
2.、Screws: Any fasteners consisting of round heads, threaded rods, or round rods are called screws. They must be tightened with a screwdriver and an Allen key, such as slotted cap screws, slotted countersunk head screws, and cross recessed countersunk heads. Screws, Hexagon socket head cap screws, Hex socket countersunk head screws, etc.; Screws screw the threads directly into the threaded holes of one of the connected parts and do not require nuts.
3、Third, the bolt: the head is generally hexagonal, the stem with external threads, fasteners tightened with a wrench is a bolt, widely used in mechanical manufacturing detachable connection, generally with a nut (usually plus a washer Or use two washers.
4、Nuts and Nuts: The nut is usually hexagonal in shape and the inner bore is internally threaded. It is used to fit the bolts and tighten the relevant parts. Nuts are commonly known, and standards should be called "nuts."
5、More fastener names are based on their appearance and role, to do the approximate classification and statement, so we have to do a good job classification and distinction for the above three categories, it is not difficult to find its characteristics.