What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The material of the rubber gasket is NBR nitrile rubber, which is the most commonly used and has the highest cost performance. The use of FFKM perfluoroelastomer gaskets is generally in the more advanced fields, such as the field of aerospace rockets. Because its price is quite expensive, but its performance is excellent and can exceed many metal materials. For specific material information, please refer to the following: Material Name Chemical Description English Abbreviation English Alias Nitrile Butadiene Rubber Acrylonitrile-Butadiene Rubber Ethylene-Propylene-Diene Rubber EPDM EP,EPT,EPR Neoprene Neoprene CR Neoprene Silicone Silicone Rubber WMQ PVMQ Fluorosilicone Fluorosilicone Rubber FVMQ FVMQ Acrylate Acrylate Rubber ACM ACM Ethylene Acrylate Vinyl -Acrylic Rubber AEM Vamac Styrene-Butadiene Styrene-Butadiene Rubber SBR SBR Polyurethane Polyester/Polyether Urethane AU/Eu AU/EU Natural Rubber Natural Rubber NR NR
In the household and industry, when installing furniture, home appliances, electrical appliances, equipment and other objects, the objects are uneven or uneven due to the uneven bottom of the object, or because the placement surface or installation surface is uneven, or because the two surfaces are different and do not fit together. stable, produce vibration, shaking or sliding, affecting the use effect and service life. Sometimes two items need to be placed next to each other, but their surfaces cannot be in direct contact, otherwise the surfaces will be damaged. For these two cases, the common solution is to install gaskets. There are two types of gaskets: wedge and flat. The wedge-shaped gasket adjusts the actual thickness by adjusting the length of the insertion gap, but the contact surface and load-bearing surface of this method are small, and due to its wedge-shaped structure, the gasket may withdraw after being stressed for a long time. Flat gaskets are generally made from local materials, using waste paper, plastic, rubber, metal and other materials to form the required thickness by folding or stacking. Such gaskets are often not quickly assembled to the exact desired thickness, are not aesthetically pleasing, and are not reusable. The purpose of Guangdong Yueluo Hardware Industry Co., Ltd. is to provide a product that can keep furniture, home appliances, equipment, electrical appliances and other objects horizontal, vertical or stable, prevent them from vibrating, shaking or sliding, and can provide appropriate thickness and beautiful appearance. gasket. The purpose of Yueluo is to realize a gasket that can be combined at will. The sheet 1 is provided with small holes 3 , and the connecting device 2 connects a plurality of sheets 1 together through the small holes 3 . The connecting device 2 is a rivet or a screw. The material of the sheet 1 can be plastic, metal, paper card or rubber. The gaskets provided by Yueluo can be combined at will. Multiple sheets are connected together by rivets or screws. By opening or closing the sheets, or dismantling the screws, the sheets are reassembled to obtain a combination of gaskets with different thicknesses and elasticity. The space between the installation object and the installation surface to keep the object horizontal, vertical or stable and prevent it from vibrating, shaking or sliding.
Inspection method There are two types of screw surface inspection, one is the inspection before the screw is produced and not plated, and the other is the inspection after the screw is plated, that is to say, after the screw is hardened and the surface of the screw is treated. . After the screws are produced and before electroplating, we inspect the screws in various aspects such as size and tolerance. See if there are national standards or customer requirements. After the surface treatment of the screws, we will inspect the plated screws, mainly to check the color of the plating and whether there are any broken screws. In this way, when we deliver screw goods to customers, customers can successfully pass the customs when they receive the goods. Inspection of screws after treatment: 1. Appearance quality requirements The inspection of the appearance of screws is carried out from the aspects of appearance, electroplating layer and so on. Second, the inspection of the thickness of the screw coating 1. The measuring tool method uses a micrometer, a vernier caliper, a plug gauge, etc. 2. Magnetic method The magnetic method is used to measure the thickness of the coating layer, which is a non-destructive measurement of the non-magnetic coating layer on the magnetic substrate with a magnetic thickness gauge. 3. Microscopy Microscopy is called metallographic method, which is to magnify the etched fasteners on a metallographic microscope with a micrometer eyepiece to measure the thickness of the coating on the section. 4. Timing flow method The timing flow method uses a solution that can dissolve the coating to flow on the local surface of the coating, and calculates the thickness of the coating according to the time required for the local coating to dissolve. There are also coating drop method, anodic dissolution Coulomb method, etc. 3. Inspection of the adhesion strength of the screw coating There are many methods for evaluating the adhesion between the coating and the base metal, usually the following. 1. Friction polishing test; 2. File method test; 3. Scratch method; 4. Bending test; 5. Thermal shock test; 6. Extrusion method. 4. Inspection of corrosion resistance of screw coatings The corrosion resistance inspection methods of coatings include: atmospheric exposure test; neutral salt spray test (NSS test); acetate salt spray test (ASS test), copper accelerated acetate salt spray test (CASS) test); and corrosion paste corrosion test (CORR test) and solution spot corrosion test; immersion test, inter-dipping corrosion test, etc.
Rivet nuts, pull caps, and instant pull caps are widely used in the assembly of electromechanical and light industrial products such as automobiles, aviation, instruments, furniture, and decoration. It is developed to solve the shortcomings of thin metal plate and thin tube welding nuts, such as easy melting and easy sliding of internal threads. Chinese name rivet nut, foreign name Rivetnut, blinddrivetnut, threadedforbid, rivnut, also known as rivet nut, is used in various metal sheets, pipes and other manufacturing industrial applications in railways, refrigeration, elevators, switches
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