Service HotlineGB6177 Hexagon Flange Nuts - Grade GB55 Hexagon Thick Nuts GB56 Hexagon Extra Thick Nuts GB1229 Large Hexagon Nuts (High Strength for Steel Structure) Lock Nuts Other Names: Root Nuts, Lock Nuts, and Nuts. Purpose: To lock the outer joint of the through wire or other pipe fittings. The working principle of the nut is to use the friction between the nut and the bolt for self-locking. However, the reliability of this self-locking is reduced under dynamic loads. In some important occasions, we will take some anti-loosening measures to ensure the reliability of the nut locking. Among them, the use of lock nuts is one of the anti-loosening measures.
Principles of stainless steel screw material selection: The selection of stainless steel materials is mainly considered from the following five aspects. 1. Requirements on mechanical properties, especially strength, of stainless steel screw materials; 2. Requirements on corrosion resistance of materials by working conditions; 3. Heat resistance of materials by working temperature (high temperature strength, oxidation resistance) 4. Requirements for material processing performance in terms of production technology; 5. Other aspects such as weight, price, procurement and many other factors must be considered.
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.
Flat washers are frequently used in mechanical connections. They are usually placed between the nut or screw head and the connected parts to prevent the screw or nut from loosening during use. The upper and lower end faces of conventional flat gaskets are mostly smooth planes, with a single structure and poor compressive capacity. When assembled with a nut or screw, the pressure on the flat washer is increased, and when it is closely rubbed with the nut or screw, it is prone to breakage, which greatly affects the quality of the product.
Hexagon head bolts are divided into two types: outer hexagon bolts and inner hexagon screws. According to the force mode of the connection, there are ordinary ones and those with reaming holes. The bolts used for reaming holes should be matched with the size of the holes and are used when receiving lateral force. According to the shape of the head, there are hexagonal head and round head. , square head, countersunk head, etc. Generally, the countersunk head is used in places where the surface is smooth and no protrusions are required after connection, because the countersunk head can be screwed into the part. The round head can also be screwed into the part. The tightening force of the square head can be Larger, but larger in size. Hexagons are the most commonly used. In addition, in order to meet the needs of locking after installation, there are holes in the head and holes in the rod. These holes can prevent the bolts from loosening when they are subjected to vibration.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: shrink rod aluminum column, locking hexagon nut, square inclined washer for channel steel, A-grade carbon steel hexagon head bolts and other products, we can provide You have the right fastener solution for you.
