How to use self-drilling screws?

1. After driving the self drilling screw into the hole on the ground or wall, tighten the nut on the self-drilling self-tapping screw with a wrench. The screw goes out, but the outer metal sleeve does not move, so the big head under the screw is Expand the metal sleeve so that it fills the entire hole, at this time, the self-drilling screw cannot be pulled out;
2. The self-drilling screw is a special threaded connection used to fix the air pipe support, crane and bracket on the wall, floor and column. It is composed of countersunk bolts, expansion tubes, flat washers, spring pads and hexagon nuts Composition, when using, you must first use an impact electric drill (hammer) to fix the corresponding size of the hole on the fixed body, and then install the bolt and the expansion tube into the hole, and tighten the nut to make the bolt, expansion tube, mounting part and the fixed body Inflation and tightness become one;
3. The self-drilling 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, and the cone moves through the axial movement of the thread. Furthermore, a large positive pressure is formed on the outer circumferential surface of the expansion tube, and the angle of the cone is very small, so that friction self-locking is formed between the wall, the expansion tube, and the cone, and then the fixing effect is achieved;
4. The spring washer on the self-drilling screw is a standard part. Because its opening is staggered and elastic, it is called a spring washer. The function of the spring washer is to use the sharp sharp angle of the wrong mouth to penetrate the nut and the flat washer to prevent the nut from loosening.