Basic requirements for bolted connections

When ordinary bolts are used as permanent connection bolts, the following requirements should be met:

1. For general bolt connections, flat washers should be placed under the bolt head and nut to increase the bearing area.

2. Flat washers should be placed on both the bolt head and nut sides. Generally, no more than two flat washers should be placed on the bolt head side, and no more than one flat washer should be placed on the nut side.

3. For bolts and anchor bolts that are designed to prevent loosening, nuts or spring washers with anti-loosening devices should be used. Spring washers must be placed on the nut side.

4. For bolt connections subjected to dynamic loads or in critical areas, spring washers should be placed as required by the design. Spring washers must be placed on the nut side.

5. When connecting I-beams and channel steel using bevels, bevel washers should be used to ensure that the bearing surfaces of the nut and bolt heads are perpendicular to the bolt shank.