In fact, the standard saying is that there are no screws and nuts.
Screws are commonly known as screws with external threads.
The nut is usually hexagonal in shape, and the inner bore is internally threaded to fit the bolt and tighten the relevant part.
Nuts are commonly known and standards should be called 'nuts'.
The head of the bolt is generally hexagonal and the stem has external threads.
The screws are small, the head has a flat head, a crosshead, etc. The stem has external threads.
The actual stud should be called "double stud", both ends have external threads, the middle is generally a polished rod. The long end of the thread is used to connect with the deep hole, and the short section is connected to the nut.
The standard fasteners are divided into twelve major categories. When selected, the fasteners should be used according to their application and their functions.
1 bolt
Bolts are widely used in machine construction for detachable connections and are generally used with nuts (usually with a washer or two washers).
2, nuts
3, screws
Screws are usually used alone (sometimes with washers). They are usually fastened or tightened and should be screwed into the body's internal threads.
Stud
The studs are mostly used to connect one of the connected parts with a large thickness, and it is necessary to use a place where the structure is compact or where bolts are not used because of frequent disassembly. Studs are generally threaded at both ends (single-ended studs are single-ended with threads), usually a thread is firmly screwed into the body of the part, and the other end matches the nut, acting as a connection and fastening, but in very To a large extent, it also has a fixed role.
5, wood screws
Wood screws are used to screw into the wood to make a connection or fastening effect.
6, self-tapping screws
The working screw hole matching with the self-tapping screw does not need to be tapped in advance, and the internal thread is formed while screwing in the self-tapping screw.
7, washers
Lock washer
The washers are used between the bearing surfaces of bolts, screws, nuts, etc., and the workpiece support surface to prevent loosening and reduce the stress on the support surface.
Lock washer
8, retaining ring
Retainers are primarily used to position, lock, or stop a part on a shaft or hole.
Industrial meson
9, the pin
Pins are usually used for positioning, they can also be used to connect or lock parts, and they can also be used as overload shear elements in safety devices.
10, rivets
One end of the rivet has a head and the stem is unthreaded. When using, insert the rod into the hole of the connected part, and then rivet the end of the rod to make connection or fastening.
11. Connections
The connecting pair is a combination of screws or bolts or tapping screws and washers. After the washer is installed on the screw, it must be able to rotate freely on the screw (or bolt) without falling off. Mainly from the fastening or tight role.