principle
The fixing principle of expansion bolts: The fixing of expansion bolts is achieved by using the slope of the arch to promote the expansion and generate frictional grip force, thus achieving the fixing effect. One end of the screw is threaded, and the other end has vertebrae. The outer layer is made of steel sheet, and half of the iron sheet cylinder has several incisions. Insert them together into the holes made on the wall, then lock the nut. The nut pulls the screw outward and pulls the cone into the steel sheet cylinder. The steel sheet cylinder is expanded and then tightly fixed to the wall. It is generally used for fastening protective fences, canopies, air conditioners, and other materials such as cement and bricks. But its fixation is not very reliable, and if there is significant vibration under the load, it may loosen, so it is not recommended for installing ceiling fans, etc.
The principle of expansion bolt is to insert the expansion bolt into the hole on the ground or wall, and then tighten the nut on the expansion bolt with a wrench. The bolt moves outward, but the outer metal sleeve does not move. Therefore, the large head under the bolt expands the metal sleeve, filling the entire hole. At this point, the expansion bolt cannot be pulled out.
Grade
The meaning of the expansion bolt with performance level 4.6 is:
1. The nominal tensile strength of the expansion bolt material reaches 400MPa level;
2. The yield strength ratio of the expansion bolt material is 0.6;
3. The nominal yield strength of the expansion bolt material reaches 400 × 0.6=240MPa level
The meaning of the performance grade of expansion bolts is an internationally recognized standard. For expansion bolts with the same performance grade, regardless of the difference in material and origin, their performance is the same, and only the performance grade should be selected in the design.
Post time: Jul-19-2024