What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The tooling for screw standard parts provided by Yueluo Guangdong Yueluo Hardware Industry Co., Ltd. mainly solves the problems of low manual operation matching efficiency, wrong specifications of screw standard parts, and easy falling of screw standard parts into the product when assembling screws in the prior art. . The specific technical solutions of Guangdong Yueluo Hardware Industry Co., Ltd. are as follows. The screw standard parts supporting tooling includes a stud sleeve hole plate, a gasket sleeve hole plate and a nut sleeve hole plate with matching structure; the stud sleeve hole plate There is at least one stud hole matching with the assembled stud structure, at least one gasket hole matching with the assembled gasket structure is arranged on the gasket sleeve hole plate, and the nut sleeve hole plate is provided with at least one gasket hole matching with the assembled gasket structure. At least one nut hole matched with the assembled nut structure; the number of stud holes, gasket holes and nut holes are equal. The above-mentioned stud sleeve hole plate is provided with a positioning device, and the gasket sleeve hole plate is provided with a matching positioning hole; or the gasket sleeve hole plate is provided with a positioning device, and the stud sleeve hole plate is provided with a matching positioning hole. The above stud holes are through holes; the nut holes are blind holes. Forty to one hundred and fifty stud holes are arranged on the stud sleeve hole plate. The above-mentioned positioning device is a positioning plate and/or a positioning column. The advantage of Guangdong Yueluo Hardware Industry Co., Ltd. is that the matching tooling for screw standard parts improves the matching quality of screw standard parts, effectively prevents screw standard parts from falling into the product easily and screw specifications are wrong; it simplifies the matching difficulty of screw standard parts and improves assembly efficiency. . The screw standard parts supporting tooling can be processed differently according to different screw standard parts specifications, and the applicability is very wide.
Many standoffs are used in sheet metal and aluminum profile processing. However, the existing pressure riveting nut column generally adopts a clearance fit between the pressure riveting and the pressed plate, which has no effect on the general pressure riveting, but it has high surface quality requirements for aluminum profiles, especially Painting aluminum profiles will have a certain impact. First, because the bottom holes of pressure riveting on aluminum profiles are generally processed on ordinary punching machines, a tapered hole with a horn will be generated, which will further increase the gap between the pressure riveting nut columns. Make the mutual tightening force smaller, causing some aluminum profile components to loosen the riveting nut when installing screws, resulting in unqualified surface quality. Therefore, we urgently need a way to reduce the matching gap with the bottom hole of the aluminum profile pressure riveting. The pressure riveting standoff is used to increase the wrapping force between the pressure riveting standoff and the aluminum profile hole.
Cross recessed pan head screws refer to cross recessed machine wire screws, which are represented by the letters PM. The country stipulates that the thread specification is M1.6-M10, the performance level is 4.8, A-50, A2-70, CU2, CU3 and AL4, H-type and Z-type cross recessed, and the product grade is Class A cross recessed pan head screws . If other technical requirements are needed, they should be selected from the current standards (such as GB/T196, GB/T3106, GB/T3098.1, GB/T3098.6 and GB/T3098.10).
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.
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