What should be paid attention to during the construction of grade 10.9 steel structure bolts? Steel structure bolt is a kind of high-strength bolt and a kind of standard parts. The fastening performance is relatively good. It is used in steel structure and engineering to make the fastening effect. In general steel structure, the required steel structure bolts are above grade 8.8, as well as grade 10.9 and grade 12.9, all of which are high-strength steel structure bolts.

What are the main factors affecting nylon lock nuts? The large tightening torque of lock nut is affected by many factors. For the study on the low cycle fatigue performance of lock nut, the pitch diameter of thread, spiral rise angle and profile angle remain unchanged, only the elastic restoring force fnmax and equivalent friction angle of thread piece ρ E there will be some changes after reuse. Therefore, it is only necessary to analyze the variation law of large screw out torque of lock nut under cyclic load from these two aspects.

We are used to calling all fasteners screws. However, screws are only a whole, which can be specifically divided into screws, bolts, etc. No, people have different understanding of screws. Building curtain wall screws are common screws at present, because they can be seen everywhere in our life, especially in windows, The screws used on the building curtain wall can be called curtain wall screws. So what are some common screws in building curtain wall?

Car oil leakage can be caused by a variety of reasons, but for car owners, it is important to maintain the vehicle. Among them, uneven tightening force of fastening nut, broken buckle or loose falling off of sliding wire will also lead to serious oil leakage. Then the majority of riders are also essential for the maintenance of each nut. 1、 Pay attention to the role of cushion The gasket between the stationary parts of the automobile plays a leak proof sealing role. If the material, manufacturing quality and installation do not meet the technical specifications, it will not play the role of sealing and leakage prevention, and even accidents will occur. 2、 All kinds of fastening nuts on the vehicle shall be tightened according to the specified torque The gasket will leak if it is too loose and not tightly pressed; Too tight will make the metal bulge around the screw hole or screw thread slip, resulting in oil leakage. In addition, if the oil drain plug of the oil pan is not tightened or loosened, it is easy to cause oil loss, and then the machine damage accident of "Bush burning and shaft holding" occurs. 3、 Replace the failed oil seal in time Many moving parts on the vehicle will throw oil due to improper installation, misalignment between the journal and the oil seal edge and deflection. Some oil seals will lose elasticity due to rubber aging if they are used for too long. 4、 Avoid blocking the check valve and vent valve After the engine ventilation system is blocked, the movement resistance of the piston is increased and the fuel consumption is increased. Due to the pressure difference inside and outside the tank shell, oil leakage at the weak seal is often caused. Therefore, the vehicle shall be inspected, dredged and cleaned regularly. 5、 Properly solve the sealing of various oil pipe joints The union nut for vehicle is often disassembled and disassembled, which is easy to break and loosen the sliding wire, which will cause oil leakage. Replace the union nut and solve the conical seal by grinding to compress the nut. 6、 Avoid hub oil spillage Excessive lubricating grease in hub bearing and cavity, or improper oil packaging, poor quality and aging failure; Excessive hub temperature caused by frequent braking; Loose axle nuts will cause oil rejection of the wheel hub.

Flat washer Washer refers to the part padded between the connected part and the nut. Generally, the flat metal ring is used to protect the surface of the connected part from the scratch of the nut and disperse the pressure of the nut on the connected part. Flat washer and spring washer Spring washer is widely used in load-bearing and non load-bearing structures of general mechanical products. It is characterized by low cost and convenient installation. It is suitable for parts with frequent assembly and disassembly. However, the anti loosening ability of spring washer is very low! Self locking nut In order to prevent this phenomenon, the self-locking nut was invented. The main function of self-locking nut is anti loosening and anti vibration. For special occasions. Its working principle is generally self-locking by friction. Self locking nuts classified by function The types are nylon ring embedded, necked and equipped with metal locking device. They are all effective torque type jam nuts. Nut locking fluid Apply the nut locking fluid to the tightening part of the bolt, and then screw on the nut to achieve the locking effect.

Compared with the physical properties of stainless steel and carbon steel, the density of carbon steel is slightly higher than that of ferritic and martensitic stainless steel, but slightly lower than that of austenitic stainless steel; The resistivity increases in order of carbon steel, Ferritic, martensitic and austenitic stainless steel; The order of linear expansion coefficient is similar, austenitic stainless steel is high and carbon steel is small; Carbon steel, ferritic stainless steel and martensitic stainless steel are magnetic, while austenitic stainless steel is non-magnetic, but it will be magnetic when it is transformed into martensite by cold work hardening. This martensitic structure can be restored by heat treatment. Austenitic stainless steel has the following characteristics compared with carbon steel: 1. High electro negative rate, about 5 times that of carbon steel. 2. The large linear expansion coefficient is 40% larger than that of carbon steel. With the increase of temperature, the value of linear expansion coefficient of stainless steel screws increases accordingly. 3. Low thermal conductivity, about 1 / 3 of that of carbon steel.