Do expansion bolts require nuts and washers?

Expansion bolts usually require nuts and washers to be used during installation. An expansion bolt is a fastener that secures itself to a substrate through the expansion of the bolt. Its working principle involves inserting the expansion bolt into a pre-drilled hole and then tightening the bolt, causing the expansion portion to expand outward and thus lock firmly against the wall of the hole. **Nut**: The function of an expansion bolt is to connect the object to be anchored with the substrate, while the nut is used to secure the anchored object and provide the necessary tightening force. **Gasket**: The function of a gasket is to provide a flat surface for bearing pressure between the bolts and the object being secured, thereby ensuring even pressure distribution. Additionally, the gasket helps to reduce damage to the surface of the object being secured when the bolts are tightened. In some cases, if the design of the expansion bolt already takes into account the distribution of the fixing force and the protection of the contact surface, it may not be necessary to use shims additionally ； The nut is essential, as it is used to apply pressure in order to expand the expanded portion and anchor it to the wall of the hole. However, whether to use shims or not still needs to be determined based on the actual installation requirements and conditions. .

A complete set of supplies – this is probably necessary in order to increase the load-bearing area. For reference.