Service HotlineIn order to overcome the above problems, Guangdong Yueluo Hardware Industry Co., Ltd. provides a screw that can be quickly installed and removed. Using the principle of lever, press the handle downward, and the screw can form a backward force through the connecting piece. Press the screw and nut tightly; lift the handle, the screw forms a forward force, and the screw can be removed. Thus, the time and manpower for screwing during installation and disassembly are reduced. The solution adopted by Guangdong Yueluo Hardware Industry Co., Ltd. to solve its technical problems is that the entire screw includes a screw rod, a nut, a connecting piece, a circlip, a positioning pin, a small shaft, a fixed piece, a base, and a handle; the screw is connected by the small shaft at the upper end. At the upper end of the connecting piece, the handle is connected to the lower end of the connecting piece, and the front end of the handle is connected to the base fixing piece through a positioning pin. There are gaps at both ends of the small shaft, and the small shaft is installed through the circlip. The front end of the handle can only be rotated on the positioning pin. Due to the lever principle, when the handle is pressed down, it will drive the screw at the front end of the connecting piece, so that the screw generates a backward force and tightens the screw and the nut. On the contrary, when the handle is pulled up, the screw generates a forward force, so that the screw can be easily removed. The beneficial effect of Guangdong Yueluo Hardware Industry Co., Ltd. is that the quick-opening screw saves the time and labor of repeatedly twisting the nut during installation and disassembly. The installation and removal process is simple.
An elastic cylindrical pin loading and unloading tool, comprising a rectangular base on which a hollow cylindrical tooling station is arranged for fixing a tooling and installing a cylindrical pin on the tooling for shear force testing, the The tooling includes an outer cylinder and an inner cylinder that are assembled together, the outer cylinder and the inner cylinder are in clearance fit, and the base is further provided with a counterbore for taking out the inner cylinder after the tooling test is completed.
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.
In the mechanical structure, the existing seals are used on the end face of the bolt or the end face of the oil joint. The copper washer is often used as the seal, and the copper washer can only be used once, and it will become hard after the second use, reducing its sealing performance. Especially when it is used on the oil drain bolt (also known as the oil drain plug) of the oil pan of the automobile engine, it is necessary to do a maintenance and replace a copper washer, otherwise it is easy to cause oil leakage. Even so, the wear of the screw hole of the engine oil pan is also very big. It is also difficult for ordinary auto repair shops to replace one copper washer at a time.
The bolt performance grade label consists of two parts of numbers, which represent the nominal tensile strength value and yield ratio of the bolt material respectively. For example: a bolt with a performance level of 4.6, its meaning is: 1. The nominal tensile strength of the bolt material is 400MPa; 2. The yield ratio of the bolt material is 0.6; 3. The nominal yield strength of the bolt material is 400×0.6=240MPa Grade 10.9 high-strength bolts, after heat treatment, can reach: 1. The nominal tensile strength of the bolt material reaches 1000MPa; 2. The yield ratio of the bolt material is 0.9; 3. The nominal yield strength of the bolt material reaches 1000×0.9=900MPa class
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: 304 hexagon socket screws, hollow wall screws, galvanized extended hexagon nuts, internal and external thread screws and nuts and other products, we can provide you with suitable screws for you. Firmware Solutions.
