What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The embedded nut is made of copper nuts made of various embossed wires (usually lead brass, such as H59, 3604, 3602). The embedded knurled copper nuts that we come into contact with on a daily basis are processed by precision automatic lathes. The reference standard for embedded knurled copper nuts comes from the national standard GB/T809. The main operation method of the anti-loose nut is to inject the embedded knurled copper nut. After heating, it is embedded into the plastic part or directly injected into the mold. If the mold is injection-molded, the melting point of PA/NYLOY/PET is above 200°C , After the embedded nut is hot melted into the plastic part, the temperature rises rapidly. After injection molding, the plastic body rapidly cools and crystallizes and becomes hard. If the embedded nut temperature is still at a high temperature, it may fall to the place where the copper nut contacts the plastic part. Start to loosen or crack. Therefore, copper nuts are used instead of carbon steel nuts in the injection molding of embedded nuts. There are two ways to form the external knurling of the embedded copper nut. One is to use copper raw material to draw the knurl and then to produce it on the upper equipment. Generally, the pattern of this method is straight, and the other is to use The round copper material is directly embossed while tapping during the production process. This processing method can produce some non-standard size knurled copper nuts. The embossed shape of the embedded copper nut can be selected by the user, such as mesh, Character embossing, herringbone embossing and other knurling patterns.
Friction type high-strength bolts: suitable for beam and column connections of steel frame structures, solid web beam connections, heavy-duty crane beam connections in industrial plants, braking systems and important structures bearing dynamic loads. Pressure-bearing high-strength bolts: Can be used for shear connections in statically loaded structures that allow a small amount of sliding or in members that are indirectly loaded with dynamic loads. Tensile high-strength bolts: When the bolts are in tension, the fatigue strength is low. Under the action of dynamic load, its bearing capacity is not easy to exceed 0.6P (P is the allowable axial force of the bolt). Therefore, it is only suitable for use under static load. Such as flange butt joints, T-joints, etc. of pressure members.
1. First remove the sludge on the surface of the broken head of the broken screw, use the center gun to kill the center gun of the section, and then use an electric drill to install a drill bit with a diameter of 6-8 mm to drill the hole in the center of the section, pay attention to the hole must be drilled through. After the hole is drilled through, remove the small drill bit and replace it with a drill bit with a diameter of 16 mm, and continue to expand and drill through the hole of the broken bolt. 2. Take a welding rod with a diameter of less than 3.2 mm and use a medium and small current to carry out surfacing welding from the inside to the outside in the hole of the broken bolt. Take half of the entire length of the broken bolt at the beginning of the surfacing welding. When starting the surfacing welding, the arc should not be too long. In order to avoid burning through the outer wall of the broken bolt, surfacing to the upper end face of the broken bolt, and then continue surfacing to weld a cylinder with a diameter of 14-16 mm and a height of 8-10 mm. 3. After the surfacing is completed, hammer the end face with a hammer to make the broken bolt vibrate along its axial direction. Due to the heat generated by the previous arc and the subsequent cooling plus the vibration at this time, the broken bolt and the thread of the body will be loose in between. 4. Carefully observe, when it is found that a small amount of rust leaks from the fracture after the knock, take the M18 nut and put it on the surfacing column head and weld the two together. 5. After welding, use a torx wrench to cover the nut while it is still hot, and twist it back and forth, or tap the end face of the nut with a small hand hammer while twisting back and forth, so that the broken bolt can be taken out. 6. After taking out the broken bolt, use a suitable tap to process the thread in the frame to remove rust and other debris in the hole.
At present, the screws used by people are not provided with a device that does not loosen, especially in some key parts, if the screws are loosened, it will cause heavy losses. In order to overcome the current situation, there is no device on the screw to prevent the screw from loosening, which may cause heavy losses. Guangdong Yueluo Hardware Industry Co., Ltd. The inner part will not be loose, and it will save people the trouble of maintenance and reduce the hidden danger of accidents. The solution adopted by Guangdong Yueluo Hardware Industry Co., Ltd. to solve its technical problems is to make a special screw and nut, set a stop groove on the screw, and then set a stop rod on the nut. After the screw is tightened , let the backstop rod be stuck in the backstop groove to prevent the screw from loosening. The beneficial effect of Guangdong Yueluo Hardware Industry Co., Ltd. is to ensure that the screws will not loosen during the service period, reducing the hidden danger of accidents and reducing the maintenance rate. Guangdong Yueluo Hardware Industry Co., Ltd. is further described below in conjunction with the accompanying drawings and embodiments
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