Yueluo relates to a self-tapping screw according to the preamble of claim 1. A self-tapping screw is known from EP0623759B1, the ratio of the outer diameter to the smaller diameter of the self-tapping screw is about 1.25-1.5, the ratio of the outer diameter to the pitch lead is about 1.5-1.6 and the thread The flank angles of , are < 50° and ≥ 35°. EP0433484B1 proposes a self-tapping screw whose thread is provided with cutting teeth of approximately arcuate design, and the cutting edge and the thread crest are at the same horizontal position and are set in opposite directions. One purpose of Yueluo is to realize a general type of self-tapping screw so that it can be screwed particularly easily into holes drilled in concrete or other materials such as bricks and the like. According to Yueluo, this object is achieved by the features in the characterizing part of claim 1, and surprisingly, it has been found that the parallel arrangement of the flanks, ie with a flank angle of about 0°, will make screwing particularly easy when screwing in , especially if the diameter of the hole varies within an allowable tolerance. One reason may be due to the fact that there is no lateral pressure on the material screwed into the thread, even if threads of different depths are cut in concrete or other materials such as brick, chipped plywood, or hardwood. The thread cuts into the material over its entire width by cutting grooves. In particular according to the embodiment of claim 3 the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
In the production process of Yueluo, according to the different gap guarantee schemes adopted in the mold design, different gap assembly adjustment methods are adopted accordingly. At present, the gasket method, light transmission method, measurement method, copper plating (zinc) method are often used Method, coating method, process allowance, locator positioning and other assembly adjustment methods. Generally speaking, for the working parts processed separately by the punch and the concave die, since the reasonable gap of the die has been formed theoretically, the assembly principle is to fix the working part that is not easy to adjust, and adjust the working part of the other working part. To change the position between the punch and the die to ensure a uniform gap, at this time, only the screws are pre-tightened, and the positioning pins are not fixed. Yueluo, however, many years of practical experience have made those skilled in the art notice that if they can pay attention to the positioning pins and use the positioning pins in a targeted manner in the mold design or manufacturing process, they can often produce miraculous results with half the effort. Therefore, it is very important to design a positioning pin for a specific mold, which is of great practical significance.
Large, countersunk, and thin rivet nuts can be produced according to different die angles. Then the cold forged rivet nut is degreasing, cleaned and annealed, and then extruded and tapped and surface electroplated. Since the rivet nut is formed by cold extrusion of low carbon steel, it has high mechanical properties. Specifically, the tensile strength of M3 is 250Kg, the shear strength is 140Kg; the tensile strength of M4 is 700Kg, the shear strength is 220Kg; the tensile strength of M5 1100Kg, shear force 380Kg; M6 tensile force 1750Kg, shear force 450Kg; M8 tensile force 2650Kg, shear force 660Kg.
GB 3098.1 Mechanical Properties of Fasteners Bolts, Screws, Studs and Nuts GB 3098.6 Mechanical Properties of Fasteners Stainless Steel Bolts, Screws, Studs and Nuts GB 3103.1 Tolerances of Fasteners Bolts, Screws and Nuts GB 5267 Electroplating of Threaded Fasteners GB 5779.1 Surface Defects of Fasteners - Bolts, Screws and Studs - General Requirements GB 5779.3 Surface Defects of Fasteners - Bolts, Screws and Studs - Special Requirements
rivet nut is a tool for riveting nuts, which can be used for riveting the nut to a sheet and has a wide range of uses. Most of the existing rivet nuts have a double-handled structure, which is complicated in structure and high in cost; and the double-handled structure generally requires both hands to operate due to the large distance between the two handles, which is inconvenient to operate. Technical realization elements: In order to solve the above technical problems, Yueluo provides a rivet nut with simple structure, low cost and convenient operation. The technical solution adopted by Yueluo is: including a fixed body, a sliding body, a guide sleeve, a nut, a hollow screw and a handle;
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: mold contour screws, hexagonal grooved nuts, double-headed nylon, flanged grooved nuts and other products, we can provide you with suitable products for you. Fastener Solutions.