Custom-made drywall nails self-tapping screws cross wood screws countersunk head self-tapping screws gypsum board nails 3/8

Screws are commonly found in machinery, electrical appliances and buildings. They are generally made of metal or plastic, cylindrical in shape, and grooves engraved on the surface are called screw threads. The main function of the screw is to join two objects, or to fix the position of an object. Screws can often be removed or re-tightened at will without compromising their efficiency. Generally, the diameter of the top of the screw is larger, and the common ones are round, square or regular hexagon. If the top is regular hexagon, you can turn the screw with a wrench. If the top is round, there will also be grooves on the front of the top, which is convenient for use screwdriver to turn the screw. *The common grooves are one-shaped, cross-shaped and square, and there are other shapes. The grooves of the existing screws are often easy to wear, which makes the screws inconvenient to use and causes the screws to be scrapped. In addition, because the screws have no chip removal The structure makes it difficult for the screw to penetrate other objects, which affects the efficiency of the screw.

In terms of inner hexagon, there are two versions of the national standard, one is GB70-76, the 76-year version, and the other is GB70-85, the 85-year version, most of which implement the DIN912 standard, so you should pay attention to the difference in actual business operations: GB70 -85 completely coincides with DIN912, so there is no difference in the use of the new standard, mainly the difference between GB70-76 and DIN912: for M8 series hexagonal products, the diameter of the round head of GB70-76 is 12.5MM, It is smaller than 13.27MM of DIN912. For M10 series inner hexagon products, the round head diameter of GB70-76 is 15MM, which is smaller than 16.27 of DIN912. For M12 series inner hexagon, the round head diameter of GB70-76 is 18MM. It is smaller than the opposite side 18.27 of DIN912, and the round head diameter of the inner hexagon GB70-76 of M16 and M20 series is 0.33MM smaller than that of DIN912, which are 24MM and 30MM respectively. DIN912 is 24.33MM and 30.33MM respectively. In addition, the width of the inner hexagon between the old standard and the German standard is different due to different standards. The inner side of GB70-76 is smaller, and it should be paid attention to in business operations.

Here Yueluo eliminates the drawbacks. The purpose of Yueluo is to provide a locking screw by which the gap existing between the locking screw and a transverse hole in a locking screw can be eliminated. Yueluo achieves the proposed object with a locking screw, which has the features of claim 4 . The line connecting the centers of gravity of the respective axially continuous orthogonal cross-sectional areas of the locking screw is regarded as a line. The advantage achieved by Yueluo can basically be seen that, due to the locking screw of Yueluo, the gap between the horizontal hole of the screw and the locking screw can be eliminated. Other advantages are as follows - the insertion accuracy and surgeon time spent remain within the range to date; - the strength of the locking screw is maintained; and - the extraction of an expired broken screw is assured. The further composition of Yueluo and Yueluo is explained in more detail below by means of schematic diagrams of parts of various embodiments.

Material and process requirements The self-tapping locking screw should be made of high-quality carburized steel cold heading, generally no larger than M12. The finished material should be drawn with a high total reduction rate before cold heading, so that the cold heading must be spheroidized. Annealing, in order to enhance the surface hardness and the toughness of the core, most of them are made of medium and low carbon steel. The chemical composition of the material in the standard is only for guidance. The C content is 0.13%~0.37%, the Mn content is 0.64%~1.71%, and the B content can reach 0.005%. The elements of S, P, Mn and Si in the commonly used steel are generally lower than those of the ordinary bolt steel of the same grade. And the surface quality of the material is strictly controlled to reduce deformation resistance and prevent deformation and cracking. Commonly used grades are 20Mn, 15MnB, SWRCH22A, 1022A and medium carbon steel, medium carbon alloy steel SWRCH35K, SCM435, SCR435, etc. Self-tapping locking screws are threads with an arc-shaped triangular cross-section, so the formulation of cold heading and wire rolling processes, as well as the design and manufacture of cold heading dies and special rolling plates are very important. Self-tapping locking screws require a high-hard surface for cutting and extruding capabilities due to the need for self-tapping low carbon steel. At the same time, there must be sufficient core strength and toughness to prevent twisting and breaking during work. The heat treatment process of this type of screw belongs to shallow carburizing. Regardless of whether it is made of low carbon steel or medium carbon or medium carbon alloy steel, its core hardness must be guaranteed to be within the range of 28~38HRC (9.8 grade) 33~39HRC (10.9 grade) and not less than the minimum tensile load of 930MPa (9.8 grade), 1040MPa (grade 10.9), depending on the material, the minimum tempering temperature is 420℃. In order to ensure that the self-tapping locking screw can be smoothly screwed into the prefabricated cylindrical hole, the end of the screw should be hardened by high-frequency quenching to ensure that at least one to three thread teeth are hardened, and the minimum surface hardness is 45HRC.

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