What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Most of the electroplating used for rivet nuts on the market is environmental protection blue zinc, because the salt spray test time of environmental protection blue zinc can reach 72 hours, that is, three days. This kind of electroplating has a longer salt spray resistance time. In fact, for example, for electroplating white nickel, the salt spray time of white nickel is relatively short, and it usually rusts in a few hours, which is less than 10 hours. However, some can be oiled for electroplating white nickel, and the salt spray time of the rivet nut after oiling can be longer. S series rivet nuts are made of free-cutting iron, which is treated after heat treatment. CLS series rivet nuts are made of easy-to-cut stainless steel. The hardness of low-carbon steel plates without surface treatment must be less than 70RB, and the hardness of stainless steel plates must be less than 80RB.
screw is a tool that uses the physical and mathematical principles of the circular rotation and friction of an object to fasten the mechanism of the object step by step. When using screws to fasten objects and parts, it is often necessary to use screws with spring washers and flat washers to lock and fix the relative position, so as to improve the stability of the fastening connection and make the screws less prone to loosening. However, in the prior art, the method of manually inserting the spring washer and the flat washer in sequence is generally used, which not only increases the workload of the staff, but also makes the installation efficiency relatively low. On the other hand, the traditional screw with a gasket only has the function of fixing, Without the function of sealing, it cannot be applied to special equipment such as oil tanks and airtight cabins. Therefore, it is necessary to design a screw that can reduce the workload and have its own sealing structure.
Stud bolts are manufactured in accordance with GB897-GB901 standards, the materials used are: Q235, 45#, 40Cr, 35CrMoA, Q345D, the specifications are: M3mm-M100mm, and the length can be customized according to user needs. High strength stud bolts, materials are 35#, 45#, 35CrMoA, 25Cr2MoV, 304, 316, 304L, 316L, 2H, 2HM, B7, B7M, B16, B8, 8, B8M, 8M, widely used in electric power, chemical industry , oil refining, valves, railways, bridges, steel structures, automobile and motorcycle accessories and other fields: generally used in mining machinery, bridges, automobiles, motorcycles, boiler steel structures, pendant towers, long-span steel structures and large buildings, etc. . Representation method of stud bolts: General stud bolts are expressed as: M12×100 GB 901-88 (standard) 35#/35# (material) 8.8 grade/8 grade (modulation grade) means: diameter = 12mm length = 100mm GB 901-88 adopts the national standard (of course, the industry standard can also be used as needed) stud bolt standard: GB 900-1988 Introduction to stud bolts Stud bolts save time and cost All stud bolt structures do not require drilling, Steps such as punching, threading, riveting, threading and finishing continue to expand the application potential of structural design, high current and small penetration. Therefore, welding to very thin sheets is possible. The workpiece for stud welding must be welded from one side. Can be soldered in all positions, with the help of extenders on vertical bulkheads that can be restricted. Since it is welded for a short time and there is little deformation after welding, no trimming is required. Because the welded structure does not require drilling, there is no leakage. The joint can achieve high strength, that is, the joint strength of stud welding is greater than the strength of the stud itself. How to install studs Good economy The advantage of other welding methods is the welding power. For mass-produced workpieces, standard studs are low cost. There are various types of equipment and welding torches, and the acquisition cost of equipment is relatively low. According to the product, it can be made into a multi-station automatic welding machine, or a high-precision gantry-type CNC automatic welding machine. Stud welding has high quality reproducibility and low rejection rate. However, in the application of stud welding, it should be noted that, like other fusion welding, there are certain restrictions on the carbon content in the steel. For structural steel studs, welding should be performed according to the recommended combination of stud material and base metal. There will be infusibility with the base metal. Combinations of stud material and base metal outside the recommended range shall be tested to determine the weldability and the product design requirements of the anchor bolt for the possibility of relevant inspection and evaluation.
Rivets refer to the parts that use their own deformation or interference to connect the riveted parts in riveting. As a common fixed connector, rivets are fixed by special pull rivets, which are easy to operate and have a wide range of applications.
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