Customized nickel-plated black-plated PWA with medium electronic small screw carbon steel cross round head with pad pointed tail self-tapping screw 3/4

Several concepts about high-strength bolts 1. According to the specified performance level of bolts above 8.8, they are called high-strength bolts. The current national standard only lists M39. For large-size specifications, especially those with a length greater than 10 to 15 times High-strength bolts, domestic production is still short-term. The difference between high-strength bolts and ordinary bolts: High-strength bolts can withstand larger loads than ordinary bolts of the same specification. High-strength outer hexagon bolts High-strength outer hexagon bolts are made of Q235 (ie A3). The material of high-strength bolts is 35# steel or other high-quality materials, which are heat-treated after being made to improve the strength. The difference between the two is the difference in material strength. From raw materials: High-strength bolts are made of high-strength materials. The screws, nuts and washers of high-strength bolts are all made of high-strength steel, such as No. 45 steel, 40 boron steel, 20 manganese titanium boron steel, 35CrMoA, etc. Ordinary bolts are usually made of Q235 (equivalent to A3 in the past) steel. In terms of strength grades: high-strength bolts are increasingly used. Two strength grades are commonly used, 8.8s and 10.9s, of which 10.9 is the majority. The strength level of ordinary bolts is lower, generally 4.4, 4.8, 5.6 and 8.8. High-strength bolts High-strength bolts are viewed from the force characteristics: high-strength bolts apply pretension and transmit external forces by friction. Ordinary bolt connection relies on the shear resistance of the bolt and the bearing of the hole wall to transmit the shear force. When the nut is tightened, the pre-pressure is very small, and its influence can be ignored. In addition to its high material strength, high-strength bolts also exert a large amount of pressure on the bolts. The pre-pressure generates extrusion force between the connecting components, so that there is a large friction force perpendicular to the direction of the screw, and the pre-pressure, anti-slip coefficient and steel type directly affect the bearing capacity of high-strength bolts. According to the force characteristics, it is divided into pressure type and friction type. The calculation methods of the two are different. The minimum specification of high-strength bolts is M12, and M16~M30 are commonly used. The performance of super-large bolts is unstable and should be used with caution in design.

An embodiment of Guangdong Yueluo Hardware Industry Co., Ltd. provides a screw slotting device, as shown in Figure 1, which includes a workbench 1, a vibrating plate 2 is arranged on the upper part of the workbench 1, and a conveying device 3 is arranged on the vibrating plate 2. Below the discharge port, the slotting device 4 is arranged on one side of the conveying device 3, and the slotting device 4 is provided with a reciprocating cutting wheel 42 that can slot the screws in the conveying device 3 when it extends out. The device 4 is also fixedly provided with a fixed wheel 48 for grinding the grooved screws. Using the screw slotting device, the screws can be automatically sorted by the vibrating plate 2, which improves the production efficiency. The reciprocating motion of the cutting wheel 42 can greatly reduce the probability of knife breakage. Sanding, fixes burrs and roughness.

The advantages of the pressure riveting nut: 1. The length guarantee of the distance range is realized, which greatly simplifies the assembly process and speeds up the production progress of the assembled spacing panel and accessories; 2. The back of the plate is completely embedded and flat, while ensuring the head of the nut column The plane is smooth with the plate; 3. The raw material is free-cutting iron or free-cutting stainless steel; the technical guide for the application of the pressure riveting standoff: 1. When selecting the standoff, it must be based on the thickness of the plate used, the exact size range, and the hardness of the low-carbon steel plate must be less than 70RB, the hardness of stainless steel plate must be less than 80RB. 2. The surface of free-cutting iron is treated, and the stainless steel maintains its original color. Users can order according to the model and specifications in the table according to their needs, or they can also make special orders according to their needs. 3. The hole size of the plate must be processed according to the tolerance size of 0-+0.075mm, and punching is recommended. 4. The installation must be realized by press riveting operation, and it must not be knocked in by impact. 5. When the material is stainless steel, the tail number should be marked with S. 6. The end face of the nut column is represented by C. 7. The length of the through-hole nut column is full wire below 10mm. If it is above 10mm, it can be reamed on the hexagonal end face (type I) or the round end face (type II).

At present, most of the thread locking structures use an integral nut and a matching external thread screw structure. To remove the nut from the screw rod, it must be completely unscrewed along the screw rod, which is time-consuming and labor-intensive. It is more inconvenient to install.

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