M4 grounding screw used to fix the grounding wire on household appliances and other equipment, the stud is cylindrical, and the thread is perpendicular to the end (section) surface. However, the screw holes on the equipment all have tapping guide grooves for sinking and guiding due to the manufacturing process requirements. When fixing the ground wire, if the screw is not positioned accurately (the screw is inclined), the screw is pressed down hard, which is easy to cause the screw and the screw. The screw hole bites the teeth, and after biting the teeth, it is easy to cause the screw to loosen or fall off, posing a safety hazard.
Compared with the prior art, the technical effect of Yueluo Company is: during the screwing process of the nut, the tube wall of the nut is elastically deformed so that the convex ring on the screw is matched with the groove on the nut, and the slope of the convex ring matches the groove. The groove wall is abutted against to limit the relative position of the nut tube and the screw shaft in the axial direction, which not only ensures the reliability of the threaded connection, but also achieves a significant anti-loosening and anti-falling effect. After the threaded connection, excessive force is applied to remove the nut and screw, so that it can be reused to save costs.
In order to solve the above-mentioned technical problems, a technical scheme adopted by Guangdong Yueluo Hardware Industry Co., Ltd. is: a rivet capable of selecting a breaking point is provided, comprising a nail body and a mandrel, and the mandrel is sequentially provided with from the head to the tail. Hemispherical head, cone and cylinder, the cones are provided with at least three, the mandrel penetrates into the nail body from the bottom of the nail body, and then goes out from the head of the nail body, the hemispherical head and the cylinder Exposed on the bottom of the nail body and the outside of the head, the cones are all arranged inside the nail body.
flat washer is a part that is placed between the connected part and the bolt to protect the surface of the connected part from being scratched by the nut and to disperse the pressure of the nut on the connected part. At present, a flat washer in the prior art generally includes a washer body; the washer body has a bolt hole in the middle for a bolt to pass through. Although the flat washer of the above structure has a simple structure, it still has a disadvantage. When the flat washer is cushioned between the connected part and the bolt, the bolt head is usually exposed outside the connection part, so the bolt head is easy to It is damaged under the impact of external force, thus affecting its fixing effect.
Usually, the forming of the bolt head adopts cold heading plastic processing. Compared with the cutting process, the metal fiber (metal wire) is continuous along the shape of the product, and there is no cut in the middle, thus improving the strength of the product, especially the mechanical properties. The cold heading forming process includes cutting and forming, single-station single-click, double-click cold heading and multi-station automatic cold heading. An automatic cold heading machine performs multi-station processes such as stamping, heading forging, extrusion and diameter reduction in several forming dies. The processing characteristics of the original blank used by the single-station or multi-station automatic cold heading machine are determined by the size of the bar with a length of 5-6 meters or the wire rod with a weight of 1900-2000KG, that is, the characteristics of the processing technology. The point is that cold heading does not use pre-cut single blanks, but uses the automatic cold heading machine itself to cut and upset (if necessary) blanks from bars and wire rods. Before extruding the cavity, the blank must be shaped. A blank that meets the technological requirements can be obtained by shaping. Before upsetting, reducing and positive extrusion, the blank does not need to be shaped. After the blank is cut, it is sent to the upsetting and shaping station. This station can improve the quality of the blank, reduce the forming force of the next station by 15-17%, and prolong the life of the die, and the bolts can be made with multiple diameter reductions. The precision that can be achieved by cold heading is also related to the selection of the forming method and the procedure used. In addition, it also depends on the structural characteristics of the equipment used, the process characteristics and its state, the precision of the tool and die, the life and the degree of wear. For high-alloy steel used in cold heading forming and extrusion, the roughness of the working surface of the cemented carbide mold should not be greater than Ra=0.2um. When the roughness of the working surface of this type of mold reaches Ra=0.025-0.050um, it has the highest life.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: external hexagon tri-combination bolts, motherboard circuit board support isolation copper column nuts, pan head bolts and nuts, black nylon screws and other products, we can provide you with The right fastener solution for you.