How to choose between flat pads and elastic pads?

　　In bolted connections, flat washers and spring washers each play an indispensable role. How should we make choices in specific applications? Next, let's delve deeper into this issue.

　　The characteristics of a flat pad are that it can increase the contact area, disperse pressure, protect bolts and connections. The unique feature of the spring pad is that its elasticity can self lock when the bolt loosens, ensuring a stable connection.

　　Selection and application of flat pads

　　Flat washer, also known as flat washer, is an important component for bolt and nut locking. It is mainly used to increase the contact area between screws and large equipment, and enhance the fastening effect. In practical applications, flat washers are often used in conjunction with nuts. When storing flat pads, attention should also be paid to sealing to ensure that the essential characteristics of the flat pad can be maintained within its validity period.

　　In harsh environments, the flat pad should be sealed with strong anti wrinkle ability to ensure that there is no leakage or screw damage in high temperature and high pressure working environments. When connecting the flat pad to the contact surface, it should also be ensured to be sealed at an appropriate temperature to avoid contamination and achieve seamless connection.

　　When selecting flat washers to be used with bolts and nuts, certain standards should be followed:

　　1. When selecting gasket materials, due to the electrochemical corrosion problem that may occur when different metals come into contact, flat gaskets that have been immersed in rust and corrosion resistant materials should be chosen. The material of the flat pad is usually the same as the connected part, such as steel, alloy steel, stainless steel, or aluminum alloy. If conductivity is required, copper or copper alloy can also be selected.

　　2. The inner diameter size of the flat pad should be selected based on the larger value of the thread or screw diameter. If the connected material is soft, such as composite material, or used in conjunction with spring washers, it is recommended to choose a flat pad with a larger outer diameter.

　　3. To prevent interference between the rounded corners under the bolt or screw head and the washer, flat washers with chamfered inner holes can be used when placing W washers under the bolt or screw head.

　　4. Steel washers should be used for important bolts with larger diameters or for applications that require enhanced resistance to compression, as well as for connections between tension bolts and tension shear composite bolts.

　　5. For areas with special requirements that require conductivity, copper gaskets can be chosen; If airtightness requirements are involved, sealing gaskets should be used.

　　The function of a flat pad:

　　1. Increase the contact area between screws and machines to protect components from damage.

　　2. Eliminate damage to the machine surface caused by spring washers during screw disassembly. When using, the sequence of spring pad flat pad should be followed, with the flat pad tightly attached to the machine surface and the spring pad located between the flat pad and the nut. In this way, the flat pad not only increases the force surface of the screw, but also provides necessary cushioning for the spring pad to prevent the screw from loosening. Although flat pads can sometimes be used as sacrificial pads, more often than not, they are used as supplementary pads or flat pressure pads. By increasing the contact area, the pressure between the nut and the equipment can be reduced, thereby providing protection. But flat washers do not have seismic resistance and cannot prevent screws from loosening.

　　The function of spring pad:

　　1. The main function of a spring washer is to firmly hold the nut against it with elastic force after tightening, preventing it from falling off. This type of washer ensures the stability of the connection by increasing the friction between the nut and bolt.

　　2. In practical applications, only spring washers are usually used. Only when special protection is required for the surface of fasteners and installation surfaces, will both flat washers and spring washers be considered.

　　3. Flat washers are commonly used in connecting components where there is a significant difference in material hardness between the two sides. By increasing the contact area and dispersing pressure, they prevent the soft material from being crushed.

　　The advantages of spring washers include:

　　Excellent anti loosening and seismic effects, low manufacturing costs, and convenient installation methods. However, the performance of spring washers is greatly affected by the material and process. If the material or heat treatment is improper, the washer may crack. Therefore, it is essential to ensure the reliability of the manufacturer when making a choice.

　　So, when to use flat washers and when to choose spring washers?

　　1. In situations where the load is small and does not bear vibration loads, only flat washers need to be used.

　　2. When the load is large or needs to withstand vibration loads, a combination of flat washers and spring washers must be used.

　　3. Spring washers are rarely used alone and are usually combined with other washers to work together.

　　Flat washers and spring washers complement each other due to their respective characteristics. Most of the time, they work together to protect components, prevent nuts from loosening, and reduce vibration. This combination method is undoubtedly a wise choice for the use of fasteners.