What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
In order to solve the problem of poor waterproof performance of the existing rivets, Guangdong Yueluo Hardware Industry Co., Ltd. provides a waterproof rivet. By arranging a figure-eight waterproof part for waterproofing on the lower end surface of the waterproof cap, when the object is riveted, The waterproof cap is subjected to the pulling force of the rivet rod and the supporting force of the object. The pulling force and the supporting force cause the waterproof cap to generate stress, which in turn causes the waterproof part of the waterproof cap to be micro-deformed in the closest contact with the object, so as to achieve a good sealing effect.
The purpose of Guangdong Yueluo Hardware Industry Co., Ltd. is to provide a fastener with a new structure with a nut, which cannot be tightened by conventional tools during use, and is suitable for special occasions requiring anti-theft.
In many national standards, there will be a division of intensity levels. Combination screws are no exception. The strength grade of the combined screw is divided according to the material of the screw wire and the hardness index of the screw wire. General combination screw materials are divided into stainless steel and iron, stainless steel is divided into stainless steel 201, stainless steel 304 and stainless steel 316 and so on. Iron is divided into three types: low carbon steel, medium carbon steel, and high carbon steel. Carbon steel combination screws refer to iron combination screws. Generally, iron combination screws are classified into grades 4.8, 8.8, 10.9, and 12.9. However, the combination screws of grade 10.9 and grade 12.9 are rarely used in the market, so we will not talk about them here. And the combination screws on the market are more commonly used combination screws of grade 4.8 and 8.8. 4.8 grade combination screws are generally made of 1010A screw wire rods. After the screw wire rods are beaten into screws, they are combined with spring flat washers. After production, this 4.8 grade combination screw does not need to be hardened. Its hardness can reach 4.8. 8.8 grade combination screws are generally made of screw wire 10B21 piers. After the screw and wire piers are made into screws, they are equipped with spring washers and flat washers. They can pass through the automatic elastic flat washer machine to rub the three pieces together. Fasten the spring-flat washer combination on the screw, and the spring-flat washer will not fall off. After the combination screw is produced, it needs to be hardened to make the hardness reach 8.8. After the hardness reaches 8.8, we need to take it for electroplating. In order to prevent hydrogen embrittlement of the spring washer in the 8.8-level combination screw with added hardness, it is easy to break. In this way, we have to perform hydrogen removal treatment on the hardened combined screws, and only after the hydrogen removal can be plated. In short, there are many kinds of standard grades of combined screw strength, but generally only two types are used in the market, one is the 4.8-level combined screw strength, and the other is the 8.8-level combined screw strength. 4.8-level combination screws are the most used in the market and customer needs, and have a wide range of applications. As for the standard strength of 8.8-level combination screws, we generally refer to 8.8-level hexagon socket head combination screws, 8.8-level pan head combination screws, and 8.8-level external hexagon combination screws. These three are more commonly used.
Head type broadcast 1. Hexagon head (hexagon head) 2. Hexagon head with flange (hexagon head with flange) 3. Square head (square head) 4. T head T head (hammer head) 5. Mushroom head (truss head) 6. Cheese head 7. Round head 8. Pan head 9. Countersunk head (flat head) 10. Raised countersunk head (oval
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