The Role of Washers in Fastener Bolted Connections

The Role of Washers in Fastener Bolted Connections

Among the many fastener connection methods, the bolt connection method is the most basic and practical along with the nut, screw and other connection methods. Although the bolt connection method is relatively simple in structure, the fastening effect it can achieve is very significant. And in the process of practical application, we often use Higher Cost Performance Washers and Bolts together to further delay the loosening of bolted connections after long-term work. So what role does the Higher Cost Performance Washer play in strengthening the anti-loosening effect of the bolted connection? The following content will answer this question from the aspects of Stainless Steel Flat Washers and Standard Spring Lock Washers.

1. The strengthening effect of Stainless Steel Flat Washers on bolted connections
1) First of all, the surface of the Stainless Steel Flat Washers series is relatively smooth, while the surface of the bolt head and nut is relatively rough. One of the functions of installing the flat washer is to separate the connecting piece from the bolt, which can prevent the connection from being scratched.
2) Reduce the pressure of the bolt on the surface of the connector. In the bolt connection mode, after the bolt head and nut are tightened, a certain amount of pressure will be generated on the surface of the connecting piece. If the surface of the connecting piece is weak in compression resistance, it is easy to be damaged. At this time, the selection of flat washers can significantly increase the pressure-bearing area of the joint, and the pressure on the surface of the corresponding joint will be significantly reduced, and it will not affect the fastening effect of the bolted joint itself.
3) In some special working scenarios, the bolt holes between the two connectors must correspond exactly, which requires that holes of different sizes must compensate each other for adjustment deviations. When the bolt hole exceeds the limit, a flat washer is required to ensure the successful connection of the bolt.
4) The length setting of the bolt hole is not static. Sometimes for the convenience of installation and adjustment, the length of the bolt hole will be selected to be longer. Thickened Stainless Steel Flat Washers or multiple flat washers are stacked for use.

2. The strengthening effect of the Standard Spring Lock Washer on the bolted connection
1) The Standard Spring Lock Washer is mainly to supplement the stress in time when the stress of the bolt connection is relaxed, especially when the clamping length of the selected bolt is short, the spring washer must be used for assistance.

2) Standard Spring Lock Washers are suitable for situations where the mechanical strength of the bolt itself is not high, and can supplement the stress of the bolt. However, if high-strength bolts are used for fastening connections, it is not suitable to use spring washers at this time. If used forcibly, it will have the opposite effect of weakening the anti-loosening effect.

3. Bolted connections without Higher Cost Performance Washers
We have roughly understood the specific role played by flat washers and Higher Cost Performance Washers in bolted connections, so under what circumstances is it unnecessary to use washer products?
1) Shear stress bolt connection is a relatively special connection method. The bolt itself in this fastener connection method does not need to be given excessive pretightening force, and the bolt will not be affected by the axial force after the connection is completed. Moreover, the bolt holes for the shear stress bolts are relatively small, and the pressure on the surface of the connector is also relatively small, so the gasket can be completely omitted in this bolt connection method.
2) When flanged Nuts or flanged bolts are used, the flanged structure itself has the effect of increasing the pressure-bearing area, so no additional gasket products are required.