The outer peripheral surface of the disposable syringes manufacturing tube forms a large positive pressure, and the angle of the cone is small, so that friction self-locking is formed between the wall, the expansion tube and the cone, thereby achieving a fixed effect. However, its fixing is not very reliable. How to use When using, you must first use an electric impact drill (hammer) to fix the holes of the corresponding size on the fixed body, and then install the bolts and expansion pipes into the holes with the expansion screws. The principle of the expansion bolt is to drive the expansion bolt into the hole on the ground or the wall, and tighten the nut on the expansion bolt with a wrench. Casing type expansion screw is mainly used for fixing soundproof walls and sanitary equipment., for fixing the hair bath equipment. Torsion flat head expansion screws can be used on cement concrete, brick walls and hollow bricks, etc. It expands, so it is tightly fixed to the wall, and is generally used to fasten protective fences, awnings, air conditioners, etc. Then lock the nut. However, its fixing is not very reliable. on cement, bricks and other materials. They don\u2019t seem to be very strong, but they are actually more powerful than many types of fixing screws. The bolt is covered with a round tube slightly larger than the diameter of the bolt. Half of the iron sheet cylinder has a number of cuts. Expansion screws are the most commonly used type of fasteners in people\u2019s lives. When the nut is tightened, the screw moves outwards. 3. Put them into the hole made in the wall. The inner diameter of the cone is larger than the inner diameter of the expansion tube. Externally forced expansion screws with internal teeth are mainly used for the hanging and piping of water pipes, electric pipes, air conditioners, expansion screws, and fixing of various angle irons and section steels. Put them together into the holes made in the wall. Explain the working principle of expansion screws. The tail of the screw is conical.