What is an expansion bolt
The expansion bolt is sleeved on the screw head by a cylinder with incomplete cracks, forming an enlarged conical single-headed nut. When the bolt is put into the hole, the conical nut head compresses and opens the cylinder liner, and the cylinder liner further compresses the hole wall to increase the static friction.
Use of expansion bolts
After driving the expansion bolt into the hole on the ground or wall, tighten the nut on the expansion bolt with a wrench, and the bolt will go out, while the metal sleeve outside will not move, so that the big head below the bolt will swell the metal sleeve all over the hole. At this time, the expansion bolt will not be pulled out.
Expansion bolt is a special threaded connector, which is used to fix air duct supports, hangers and brackets on walls, floors and columns. It consists of countersunk head bolt, expanding tube, flat washer, spring pad and hexagon nut. When in use, a hole with corresponding size must be punched on the fixed body with an electric drill (hammer), and then the bolt and the expansion tube are put into the hole, and the nut is tightened, so that the bolt, the expansion tube, the mounting piece and the fixed body expand into a whole.
Matters needing attention in expansion bolt construction:
1, drilling depth: The relevant information introduces the length of the expansion pipe, but I found that this depth is not enough in the specific construction, which may be related to the amount of debris left in the hole, so it is better to be about 5 mm deeper than the length of the expansion pipe. In addition, for general M6 anti-collision bolts, the drilling diameter is φ 10.
2. Of course, the requirement of the expansion bolt on the ground is that the harder the better, which also depends on the stress of the object that needs to be fixed. The mechanical strength of concrete (C 13- 15) is five times that of brick.
3. An M6/8/ 10/ 12 expansion bolt is correctly installed in concrete, and its maximum static stress in the ideal state is120/170/320/510 kg respectively. (Note that vibration will loosen bolts)
Expansion bolt is a special threaded connector, which is used to fix air duct supports, hangers and brackets on walls, floors and columns. It consists of countersunk head bolt, expanding tube, flat washer, spring pad and hexagon nut. When in use, it is necessary to punch a hole with a corresponding size on the fixed body with an impact electric drill (hammer), then put the bolt and the expansion tube into the hole and tighten the nut, so that the bolt, the expansion tube, the mounting piece and the fixed body expand into a whole.