Bolts, screws, and screws are no longer silly and unclear.

Usually we often mention bolts, screws, screws, etc. What are the differences and connections between them?

In fact, the standard is that there are no screws and nuts. Screws are commonly known as "screws" with external threads. The shape of the nut is usually hexagonal, and the inner hole is internally threaded to match the bolt and tighten the relevant parts. The nut is a common name and the standard should be called "nut". The head of the bolt is generally hexagonal and the stem has external threads. The screw is small, the head has a flat head, a crosshead, etc., and the stem has external threads. The studs should actually be called "double studs", with external threads on both ends, and the middle is usually a polished rod. The long end of the thread is used to connect to the deep hole and the short one is connected to the nut.

Standard fasteners are divided into 12 categories, which are determined according to the use of fasteners and their functions.

1, bolt

Bolts are widely used in mechanical construction for detachable connections and are typically used with nuts (usually with a washer or two washers).

2, nut

3, the screw

Screws are usually used separately (sometimes with washers) and are generally tightened or tightened and should be screwed into the internal threads of the body.

4, stud

Studs are often used to connect one of the connected parts to a large thickness, which requires a compact structure or a place where bolting is not necessary due to frequent disassembly. Studs are generally threaded at both ends (single-headed studs are single-ended with threads). Usually, one thread is screwed into the body of the component, and the other end is matched with the nut to connect and fasten, but it is very To a large extent, it also has the effect of spacing.

5, wood screws

Wood screws are used to screw into the wood for connection or fastening.

6, self-tapping screws

The working screw hole matched with the self-tapping screw does not need to be tapped in advance, and the internal thread is formed while the self-tapping screw is screwed.

7, gasket

The gasket is placed between the bearing surface of the bolt, the screw and the nut, and the workpiece supporting surface to prevent loosening and reduce the stress on the bearing surface.

8, the retaining ring

The retaining ring is primarily used to position, lock or retract the part on the shaft or in the hole.

9, sales

Pins are often used for positioning, and can also be used to attach or lock parts, and can also be used as an overload shearing element in safety devices.

10, rivets

The rivet has a head at one end and the stem is unthreaded. In use, the rod is inserted into the hole of the connected piece, and then the end of the rod is riveted for connection or fastening.

11, connection vice

The connection pair is a combination of screws or bolts or self-tapping screws and washers. After the washer is attached to the screw, it must be able to rotate freely on the screw (or bolt) without falling off. Mainly used for fastening or tightening.

12, other

Mainly including welding nails and other content.

The principle of selection of fasteners

1 From the perspective of the efficiency of processing and assembly, the types of fasteners should be minimized in the same machinery or engineering;

2 For economic reasons, it is preferred to use commodity fasteners.

3 According to the expected use requirements of the fasteners, the selected varieties are determined according to the type, mechanical properties, precision and thread.

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