Service HotlineMaterials and main equipment: 1.1 Bolts, nuts and washers shall be accompanied by quality certificates and shall comply with design requirements and national standards. 1.2 The high-strength bolts should be stored in categories according to their specifications, and should be protected from rain and moisture. Do not use if the bolts and nuts are not matched and the threads are damaged. If the bolts, nuts and washers are corroded, the tightening axial force should be sampled and used only after meeting the requirements. Bolts, etc. shall not be contaminated by soil or oil, and shall be kept clean and dry. It must be used in the same batch according to the batch number, and must not be mixed or mixed. 1.3 Main tools: electric torque wrench and controller, manual torque wrench, manual wrench, wire brush, tool bag, etc. 2 Operating conditions: 2.1 Friction surface treatment: The friction surface is treated by sandblasting, grinding wheel grinding and other methods, and the friction coefficient should meet the design requirements (a requirement is that the Q235 steel is above 0.45, and the 16 manganese steel is above 0.55). The friction surface wood is allowed to have residual iron oxide scale. The treated friction surface can generate red rust surface and then install the bolts (generally stored in the open air for about 10d). The sandblasted friction surface can be installed without rusting. When grinding with a grinding wheel, the grinding range is not less than 4 times the diameter of the bolt, the grinding direction is perpendicular to the direction of force, and the friction surface after grinding should be free of obvious unevenness. The friction surface should be prevented from being polluted by oil or paint. If polluted, it should be cleaned thoroughly. 2.2 Check the hole size of the bolt hole, the burrs on the edge of the hole must be removed. 2.3 The bolts, nuts and washers of the same batch number and specification should be packaged for use. 2.4 Electric wrenches and manual wrenches should be calibrated.
At present, the nut is used as the main body through the riveting connection with the gasket, which is more and more widely used in the industrial field, especially the automobile industry. The gasket connected with the nut has two types: spring gasket and flat gasket. After the nut is tightened, the washer gives the nut an elastic force, which is pressed against the nut to make it not easy to fall off; and the function of the flat washer is to increase the contact area between the nut and the coupling, increase the friction force, reduce the pressure per unit area and protect the surface of the connected parts. Not damaged, stop the nut from loosening. Therefore, gaskets have a wide range of applications in the field of fastening connections, and it is more and more important to improve production efficiency, reduce production costs, and meet growing demands.
At present, the commonly used shaft retaining rings in the market usually include elastic retaining rings and screw locking retaining rings, but they all require tools to be installed and disassembled, which is relatively inconvenient to use.
Bolt material: 18Cr2Ni4W, 25Cr2MoV steel; bolt specification: M27～M48. Because this kind of steel is easy to form a passivation film on the surface, and this passivation film will make the bolt unable to obtain a good adhesion chemical nickel phosphorus layer, so special pretreatment measures must be taken to remove the film first, and measures should be taken To prevent its regeneration, it is possible to ensure a good bonding force between the plated coating and the substrate. At the same time, due to the large geometric size of the bolt, it increases the difficulty of nickel-phosphorus plating treatment and quality inspection of the process.
The locking effect of the spring washer is general, and the important parts are used as little or not as possible, and the self-locking structure is adopted. For spring washers used for high-speed tightening (pneumatic or electric), it is best to use surface phosphating washers to improve their anti-wear performance, otherwise it is easy to burn out or open mouth due to friction and heat, and even damage the surface of the connected parts. For thin plate joints, spring washer construction should not be used. According to statistics, spring washers are used less and less in automobiles.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: 304 non-standard fasteners, supply nuts, round head screws, left-handed anti-thread bolts and other products, we can provide you with fastening suitable for you piece solution.
