Installation Steps And Precautions Of Internal Expansion Bolts

The inner expansion bolt is a new type of fastener. The inner expansion screw is composed of a screw and an expansion tube. The tail of the screw is conical. The diameter of the cone is larger than the inner diameter of the expansion tube. When the nut is tightened, the screw moves outward. The axial movement of the thread moves the cone part, and then a large positive pressure is formed on the outer surface of the expansion tube bolt type composite cable bracket, and the angle of the cone is small, so that friction between the wall, the expansion tube and the cone is formed. Lock to achieve a fixed effect.

Installation steps of inner expansion bolt:

1. Select an alloy drill bit that matches the outer diameter of the inner expansion bolt, then drill according to the length of the inner expansion bolt, drill the hole to the depth you need for installation, and then clean the hole.

2. Install the flat washer, spring washer and nut, turn the nut to the bolt and end to protect the thread, and then insert the inner expansion bolt into the hole.

3. Twist the wrench until the surface of the washer and the fixture are flush. If there is no special requirement, generally tighten it by hand and then use the wrench to turn it for three to five rotations.

Precautions for internal expansion bolt construction:

1. Punching depth: The relevant information describes the length of the expansion tube, but I found that the depth is not enough in the specific construction, which may be related to the amount of debris in the hole. about. As long as you are greater than or equal to the length of the expansion tube, the length of the inner expansion bolt left in the ground is equal to or less than the length of the expansion tube.

2. The requirements of the internal expansion bolts on the ground are of course the harder the better, which also depends on the stress of the objects you need to fix. The mechanical strength installed in the concrete (C13-15) is five times that in the brick body.

3. After an M6 / 8/10/12 inner expansion bolt correctly installed in the concrete, its least ideal maximum static force is 120/170/320/510 kg, respectively.