Fasteners

　　Let's start with the definition of fastener, which refers to the general name of a kind of mechanical parts used to fasten two or more parts (or components) into a whole.

Fasteners are a kind of mechanical parts used for fastening and connection and widely used. Therefore, all kinds of fasteners can be seen on all kinds of machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, meters and supplies.

Fasteners are characterized by a wide variety of specifications, different performance and uses, and a high degree of standardization, serialization and generalization. Therefore, some people refer to a class of fasteners with existing national standards as standard fasteners, or standard parts for short. Fasteners are the most widely used mechanical basic parts.

Fasteners have different inspection methods. The most important link is quality control. First of all, the feed is related to appearance, size, elements, performance, detection of harmful substances, etc; In terms of process, it is more about appearance, size, knocking experiment and forging flow line; Heat treatment is more about appearance, hardness, torque, tension, metallography and so on; Surface treatment is more about hydrogen embrittlement test, coating, salt spray, etc., including a harmful substance test for shipment.

It usually includes the following 13 types of parts: bolts, studs, screws, nuts, self tapping screws, wood screws, washers, retaining rings, pins, rivets Screw, stud and welding wire assemblies.

Fastener treatment: generally, surface treatment is required. There are many kinds of fastener surface treatment, such as electroplating, oxidation, phosphating, non electrolytic zinc sheet coating treatment, etc.

Fasteners information

Function difference between spring gasket and flat gasket:

1. Difference of locking function:

The flat gasket has no function of loosening.

2. Different functions:

The function of flat gasket is to increase the fastening contact area, and the function of spring gasket is to prevent looseness in places with vibration.

3. Use different places:

Due to the material and process limitations of fasteners such as bolts, the support surface is small. Therefore, it is necessary to reduce the compressive stress of the bearing surface and protect the surface of the connected parts. At this time, flat pads must be used.

If the spring washer is not added to the bolt connecting the motor and the base, the motor vibration will loosen the nut. Therefore, the spring gasket must be installed on the fastener with vibration equipment.