What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Now the screw itself is made of metal, so it is easy to rust, especially screws in harsh weather environments that are exposed to the air for a long time, such as air conditioners, wires, etc. In the existing technology, the shape of the screw has been fixed, and the structure of the screw itself is composed of a shaft with twill in the middle and a polygonal structure with stripes on the outside. OK, but because of the installation of some equipment, it needs to be exposed to the air for a long time. For example, the outdoor unit of the air conditioner must be installed in the outdoor area, and the outdoor can not be sheltered from wind and rain, so after long-term sun and rain, the screw The surface is easy to rust. If the rust is serious to a certain extent, the nut will be embroidered to death. Once the external machine needs to be disassembled one day, the embroidered screw will lose its use value and give workers to the workers. The disassembly and assembly of the screw has caused a lot of trouble, because the embroidered screw cannot be unscrewed directly. The only method used is to cut off the shaft in the middle of the screw with a hacksaw, or discard the entire screw structure. Since the shaft in the screw has been inserted into the middle of the wall, this waste is not good for both aesthetics and safety. To solve the rust problem of the screw, the existing technology is to improve the material of the screw, or to maintain it regularly, but this method itself is time-consuming and labor-intensive, and it is a waste of resources.
Pre-embedded copper nuts with straight pattern/twill pattern/herringbone embossing and other various anti-skid patterns can be completed at one time by automatic lathes. More complex copper nuts are processed by forming knives and table turning/tapping. Many products processed after machining are relatively simple reticulated copper nuts and straight-grained copper nuts, which are made of C3604 easy-turning brass. The surface pattern is directly drawn from the original bar, and the pattern is full and the tooth peak and bottom are clearly visible. Injection molding into plastic parts Afterwards, it can bear more high torque.
The main operation method of the embedded knurled copper nut of the lock nut is injection molding. After heating, it is embedded into the plastic part or directly injection molded. If injection molding is used, the melting point of P/NYLOY/PET is above 200°C. , After the embedded nut is hot melted into the plastic part, the temperature rises rapidly. After injection molding, the plastic body rapidly cools and crystallizes and hardens. If the embedded nut temperature is still at a high temperature, it may fall to the place where the copper nut contacts the plastic part. Start to loosen or crack. Therefore, copper nuts are used instead of carbon steel nuts in the injection molding of embedded nuts.
rivet is a nail-shaped object used to join two parts or components with a through hole and a cap on one end. In riveting, the riveted parts are connected by their own deformation or interference. There are many types of rivets, and they are informal. Commonly used are R-type rivets, fan rivets, blind rivets, blind rivets, tree rivets, semi-circular head, flat head, semi-hollow rivets, solid rivets, countersunk head rivets, blind rivets, hollow rivets, these usually use their own deformation Connect the riveted parts. Generally less than 8 mm with cold riveting, larger than this size with hot riveting. But there are exceptions. For example, the nameplate on some locks is riveted by the interference between the rivet and the lock body hole.
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