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In summary, in 2023, the overall actual supply on the structural steel supply side has not changed much. However, with the increase in production capacity, market competition pressure has further increased. The demand side has improved significantly compared with 2022. However, combined with the pressure brought by high inventory at the beginning of the period, the total supply It is still greater than the total demand, driving the overall price decline. For 2024, the competitive pressure on the supply side will not decrease, and the process of "general to excellent" will not change. Market supply may remain high. However, affected by policies and its own cyclical changes, the demand side in 2024 is expected to continue the improvement since the second half of the year. , the price center of gravity is expected to move slightly upward. The economic situation at home and abroad in 2023 will be more complex and changeable. Although a series of macro-consumption measures are frequently implemented, the downstream demand in the steel market is weak due to factors such as declining real estate and infrastructure investment. Coupled with rising raw material prices, structural steel prices are at a high level. In the ongoing game between costs, strong expectations and weak reality, steel prices have shown an overall decline. However, judging from the performance in the fourth quarter, demand has gradually exerted force to drive a more obvious recovery in prices.

Recently, with the increase in market demand, the sales volume of stainless steel products, fasteners, stamping parts, bars, wires, profiles, metal products, and hardware products have shown an obvious growth trend. According to market research data, stainless steel products are increasingly used in construction, home decoration, machinery manufacturing and other fields. They are favored by consumers because of their corrosion resistance, high temperature resistance, and beautiful appearance. Products such as fasteners and stamping parts are also widely used in the automotive, electronics, aerospace and other industries, and market demand continues to grow. Bars, wires, profiles and other products play an important role in construction, machinery manufacturing, shipbuilding and other industries. With the continuous advancement of national infrastructure construction, the sales volume of these products is gradually increasing. Metal products and hardware products play an indispensable role in home furnishing, construction, electronics and other fields, and market demand is growing steadily. Industry insiders said that with the continuous development of my country's economy and the continuous optimization of the industrial structure, the market prospects for stainless steel products, fasteners, stamping parts, bars, wires, profiles, metal products, and hardware products are broad, and future sales are expected to continue Maintain growth momentum. At the same time, industry competition will become more intense, and companies need to continuously improve product quality and service levels to meet market demand and win the trust and support of more customers.

Recently, the sales industry of stainless steel products, fasteners, stamping parts, bars, wires, profiles, metal products, and hardware products has ushered in a wave of new development opportunities. According to industry data, with the rapid development of the domestic economy and the continued boom of the construction industry, the demand for stainless steel products and other related products continues to increase, and the market potential is huge. Stainless steel products have always been widely used in construction, home furnishing, machinery manufacturing and other fields. They have the advantages of corrosion resistance, beautiful appearance and long service life, and are deeply loved by consumers. With the rapid development of the domestic construction industry, the sales volume of stainless steel products has also shown a continued growth trend. Fasteners, stamping parts and other products, as important components of stainless steel products, also occupy an important position in the market. Fasteners are an indispensable connecting element in construction, machinery manufacturing and other industries, while stamping parts are widely used in automobiles, electronics, home appliances and other fields. With the development of domestic manufacturing industry, the demand for fasteners and stamping parts is also increasing, and the market potential is huge. At the same time, products such as rods, wires, and profiles are also showing good sales momentum in the market. As a common metal material, rods are widely used in construction, machinery manufacturing, aerospace and other fields; wires are mainly used in wires and cables, welding materials, etc.; profiles are widely used in construction, home furnishing, decoration and other fields. With the continuous advancement of domestic infrastructure construction, the demand for products such as bars, wires, and profiles is also increasing year by year. Metal products and hardware products, as derivatives of stainless steel products, are also showing strong sales momentum in the market. Metal products include various metal parts, accessories, etc., which are widely used in machinery manufacturing, automobile manufacturing and other fields; hardware products include various door and window accessories, household hardware, etc., and are an important part of home decoration and household products. With the continuous development of the domestic manufacturing and home furnishing markets, the market demand for metal products and hardware products is also increasing. Faced with market opportunities, companies selling stainless steel products, fasteners, stamping parts, bars, wires, profiles, metal products, and hardware products have increased their efforts in product research and development and marketing, and improved product quality and service levels. Meet consumer needs. At the same time, the company has also strengthened cooperation with suppliers and partners to jointly promote the development of the industry. It is foreseeable that the sales industry of stainless steel products, fasteners, stamping parts, bars, wires, profiles, metal products, and hardware products will usher in broader development prospects. With the continuous development of the domestic economy and the increase in market demand, relevant enterprises will continue to increase investment, improve product quality and service levels, and make greater contributions to the prosperity and development of the industry.

The correct installation of fasteners is crucial for the safety and reliability of any given application, be it structural or mechanical. This is why we place great emphasis on understanding assembly techniques for the extensive range of fasteners we have available, offering insight and peace of mind to ensure fasteners are installed correctly and securely. We have a deep understanding of the factors that affect torque, such as the type of material being fastened, the size and grade of the fastener, and the type of connection being created.

Choosing the right fastener supplier is crucial for ensuring the quality, reliability, and efficiency of your projects. Here are some important factors to consider before making your decision:Quality of Products: The most important factor is the quality of the fasteners they supply. Ensure that the supplier offers products that meet industry standards and are made from high-quality materials to prevent failures or accidents. Range of Products: Look for a supplier that offers a wide range of fasteners, including various types, sizes, and materials. This ensures that you can find the right fasteners for different applications without having to deal with multiple suppliers.

Hexagonal bolts are a common type of fastener, and their hexagonal head can provide better torque transmission effect, making tightening easier and more stable. At the same time, the structure of the hexagonal bolt also makes it have higher tensile strength and torque bearing capacity, suitable for the fastening needs of various important mechanical equipment and structures. Our hexagonal bolts are made of high-quality materials and undergo precise processing and heat treatment to ensure their excellent performance and durability. We also provide various specifications and sizes of hexagonal bolts to meet the needs of different applications. If you need reliable fasteners to ensure the safety and stability of your equipment and structure, our hexagonal bolts will be your best choice. We will wholeheartedly provide you with high-quality products and services, making your work easier and more efficient.

Name of common fasteners Split washer Flat washer Self tapping screw Self drilling screw Drywall screw High low screw Colleted screw Concrete screw Tri-lobular thread screw Kep nut Acorn nut cap nut stainless steel screw wire Wing washer Eye bolt Piston bolt piston screw Winding bolt coil screw Hexagon head bolts Hexagon flange bolts Carriage bolt Square head bolt Flat counterlink square neck bolts Flat counter sunk nib bolts Cross received pan head tapping screws

In general, we need to consider the following aspects when selecting stainless steel materials for fasteners: 1. Requirements on mechanical properties of fastener materials, especially strength. 2. Requirements of working conditions on corrosion resistance of materials. 3. Requirements of working temperature on heat resistance (high temperature, strength, oxidation resistance) of materials. 4. Requirements for material processing performance in terms of production process. 5. Other aspects, such as weight, price and purchase, should be considered. Through the comprehensive and comprehensive consideration of these five aspects, the brand, variety, specification and material standard of fasteners are finally determined. What are the common stainless steel materials for fasteners? 1. Austenitic stainless steel The commonly used grades are 302, 303, 304 and 305, namely the so-called "18-8" austenitic stainless steel. Both corrosion resistance and mechanical properties are similar. The starting point for selection is the production process method of fasteners, which depends on the size and shape of fasteners, and also depends on the quantity of production. Type 302 is used for machined screws and self tapping bolts. In order to improve the cutting performance of Type 303 stainless steel, a small amount of sulfur is added to the Type 303 stainless steel for processing nuts with bars. Type 304 is suitable for processing fasteners with hot heading process, such as bolts with long specifications and bolts with large diameters, which may be beyond the scope of cold heading process. Model 305 is applicable to processing fasteners by cold heading process, such as cold formed nuts and hexagon bolts. The Cr content and Ni content of Type 309 and Type 310 are higher than those of Type 18-8 stainless steel, and they are suitable for fasteners working at high temperatures. Type 316 and 317 both contain alloy element Mo, so their high temperature resistance and corrosion resistance are higher than those of type 18-8 stainless steel. 321 and 347, 321 contains relatively stable alloy element Ti, and 347 contains Nb, thus improving the resistance to intergranular corrosion. It is applicable to fasteners that are not annealed after welding or serve in 420~1013C.

v1. Importance of fasteners If the force is too small, the gasket may not be in place; Too much force will wear the thread. According to the recently released data, 23% of the maintenance problems in the automotive industry are caused by loose fasteners, and 12% of new cars have incorrect fastener tightness. Bolt is one of the most important factors that determine the assembly quality. The failure of threaded fasteners to achieve the corresponding capacity is an important reason for assembly accidents! 2. Fastener bolt tightening principle The bolted connection must be able to resist the action of external forces, so that the assembled parts will not move in the direction of separation, otherwise it will cause the loosening, damage or falling off of the bolted joint. Therefore, we must design the minimum clamping force of the bolt to prevent the clamping part from being separated due to external forces, and maintain friction clamping or ensure sealing, etc. The bolt is inserted into the connected part and tightened with a nut or internal thread to make the bolt stretch and deform. This elastic deformation generates an axial tension, squeezing the clamped parts together, which is called preload. In theory, as long as sufficient clamping force is generated, the clamped parts can be fully guaranteed to work safely in harsh environments such as vibration, high and low temperatures, without the use of auxiliary methods such as gluing.

Fasteners - Fundamentals of Screws 1. Terminology Relating to Screws ● Difference of screws, screws, bolts and fasteners. ● Common English expression: screw/screw - Screw; Bolt; Fastener. ● Definition of thread: the thread is a shape with uniform spiral bulge on the external or internal surface of a solid. 2. Function of thread ● Fastening and connection functions: applicable to most screw products at this stage. ● Driving action (displacement action): such as micrometer used by QC to check dimensions. ● Sealing function: such as connection and sealing of pipes. 3. The history of thread development Machine Screw → Self Tapping Screw → Self Drilling Tapping Screw. ● Machine thread: during assembly, drill and tap the thread on the assembly first. The specification of the tapped internal thread is consistent with that of the external thread of the screw. Use a small torque for assembly. ● Self tapping thread: during assembly, drill holes on the assembly first, without tapping the internal teeth, and use a large torque for assembly. ● Self drilling thread: it is directly used on the assembly, and the screw drilling and tapping are formed at one time. 4. Screw processing method ● Turning: make the material reach the expected shape by removing the material. Advantages: high processing precision, no mold limitation. Deficiency: high production cost and slow processing speed. ● Forging: extrude the material with external force to deform it to achieve the desired shape. Advantages: fast production speed, low cost, suitable for mass production. Inadequate: The forming is limited by the mold, and the mold cost of complex products is high. 5. Cold heading process ● Cold heading: It refers to the process of extruding and deforming the metal wire with the help of external force by using the die under the condition that the metal wire is not heated. ● Cold heading process is only one kind of forging process. 6. Common raw materials for manufacturing screws ● Metal and nonmetal. ● Metals: Fe, Cu, Al. ● Iron: carbon steel, alloy steel, stainless steel. ● Form of raw materials (wire and bar). ● Processing technology of raw materials. ● Current sources of metal materials: Japan/South Korea, Taiwan, mainland China. 7. Screw standard ● National standards: GB National Standards, BS British Standards. ● Industry standards: SAE American Society of Automotive Engineers, AISI American Iron and Steel Institute, JCIS Japanese camera industry standard, DIN German industry standard JIS Japanese industry standard. ● Enterprise standards: GE American General Motors Standard, IBM Standard, SONY Standard

The principle of selecting stainless steel materials for fasteners. Generally, we need to consider the following aspects: 1. Requirements on mechanical properties, especially strength, of fastener materials. 2. Requirements of working conditions on corrosion resistance of materials. 3. Requirements of working temperature on heat resistance (high temperature, strength and oxidation resistance) of materials. 4. Requirements for material processing performance in terms of production process. 5. Other factors, such as weight, price and procurement, should be considered. After comprehensive consideration of these five aspects, the brand, variety, specification and material standard of selected fasteners are finally determined.

Do you want to add washers to the bolt connection? We often see that some bolt connections use washers, some bolt connections do not use washers, some bolt connections use flat washers, some use spring washers, and some use spring washers and flat washers. Flat washer When the bolts need to be removed frequently, in order to protect the surface of the connected parts from being scratched, it is generally necessary to place a flat washer at the nut or bolt head, so as to prevent the surface of the connected parts from being scratched, especially for the surface processed by precision machining. At some joints where the friction coefficient is required to be accurate, there is no separate test requirement for the friction coefficient. For example, in the bolted connection of wind power, bolts, nuts and washers are generally purchased. In this case, the bolts, nuts and washers are provided by the same manufacturer. The bolt manufacturer needs to treat the nuts and washers accordingly to ensure that the friction coefficient between the nuts and washers is consistent. At the same time, the supplier is required to test the torque coefficient to meet the technical requirements. When the bolt strength is relatively high and the allowable compressive stress of the connected part is relatively low. For example, the lightweight requirements of automobiles are becoming higher and higher. Lightweight connection technologies and structures are widely used in the body and even chassis structural parts. In order to reduce the compressive stress of the pressure bearing surface of the connected parts in the bolted joints and prevent crushing and permanent plastic deformation, flat washers are generally required. In addition, in bolt connection, the pressure transmission on the bearing surface of the bolt head or nut is gradually expanded in a trumpet shape. The larger the bearing surface is, the smaller the compressive stress is. Therefore, adding a flat washer can reduce the compressive stress on the contact surface of the connected part and ensure the effectiveness of bolt connection. In some cases, for example, most automobiles use stamping parts and welding parts, and the positions of the holes between the two parts can not be accurately matched. In order to ensure one-to-one correspondence between the bolt holes of the two connectors, we need to increase the diameter of the hole to compensate for the positional deviation of the hole. When the bolt hole exceeds the standard requirements, the compressive stress exceeds the strength of the material. In this case, we need to add a flat washer. Sometimes, in order to facilitate installation and adjustment, for example, when the control arm bracket is connected with the control meter, one of the two bolt holes will be made into a long hole, so that the installation position of the workpiece can be adjusted within a certain range. When a long hole is used, a thickened flat washer must be used, and even a special washer or multiple washers may be used according to specific conditions. Spring washer The main purpose of the spring washer is to relax. It is generally used in situations where the bolt preload is not high and the dynamic load is small. At present, a large number of tests have confirmed that the spring washer has little anti loosening effect. Therefore, it is not recommended to use the spring washer for tightening occasions with high preload and important connections. However, for the electrical connection joint, the spring washer still has a certain effect when it is finally completely loosened, especially when it is loosened to a certain extent, a certain preload can still exist when the preload is small. At this time, the spring washer can still play a certain role than the effect without the spring washer. When the clamping length of the bolt is short, the stress relaxation of the bolt is obvious, and the spring washer can compensate for the stress relaxation. Of course, at this time, it can be considered to use the disc spring instead of the spring washer, and the disc spring can be more evenly distributed in the axial pressure. Some experiments show that, under dynamic load conditions, the spring washer of high-strength bolt connection has almost no anti loosening effect, and it will also cause the rapid attenuation of bolt clamping force. Therefore, the spring washer is rarely used in high-strength bolt connection abroad. We have already made it clear under what circumstances washers are required for bolt connection, and under what circumstances washers can not be used? Generally, washers are not required for connection of shear stress bearing bolts (reamed hole bolts). First, shear stress bolts do not need too much pre tightening force and do not bear axial force during work. In this case, bolt holes are generally small, and the bearing surface of nut or bolt head is generally large. It is not necessary to reduce the compressive stress, and the connected parts can bear it. When using the flange nut or bolt, because the contact area of the flange bolt or nut is large, the washer is usually no longer required to increase the contact area and reduce the compressive stress.

Common misunderstandings and selection principles of fasteners Selection principle of fasteners 1. Determine category Standard fasteners are divided into ten categories, and the selection should be determined according to the application occasions and functions of standard fasteners. ① Bolt: the bolt is generally matched with the nut (usually with one washer or two washers), which is used for connection and fastening. ② Nut: the nut is matched with the bolt. ③ Screws: screws are usually used alone (sometimes with washers) and generally play a fastening or tightening role. ④ Studs: studs are generally threaded at both ends (single head studs are threaded at one end). Usually, one end of the thread is firmly screwed into the body of the component, and the other end is matched with the nut, which plays the role of connection and fastening, but also has the role of spacing to a large extent. ⑤ Washer: the washer is used between the bearing surface of bolts, screws and nuts and the process bearing surface to prevent looseness and reduce the stress of the bearing surface. ⑥ Self tapping screw: the screw hole of the workpiece matched with the self tapping screw does not need to be tapped in advance. While screwing in the self tapping screw, the internal thread is formed. ⑦ Rivet: one end of the rivet has a head, and the rod has no thread. When in use, insert the rod into the hole of the connected part, and then rivet the end of the rod to connect or fasten. ⑧ Pin: when in use, the pin is inserted into the workpiece and usually plays the role of connection or positioning. ⑨ Retaining ring: the retaining ring is usually on the shaft or in the hole to limit the axial direction of the workpiece. ⑩ Wood screw: wood screw is used to screw into wood for connection or fastening. 2. Determine standards and varieties 1. Selection principle of varieties: (1) considering the working efficiency of processing and assembly, the variety of standard parts should be minimized in the same machinery or project. (2) from the perspective of economy, the varieties of commodity standard parts should be preferred. (3) according to the expected use requirements of standard parts, the varieties shall be selected according to the type, mechanical performance, accuracy, thread and other aspects. 2. Type: (1) bolt: ① General purpose bolts: there are many varieties, including hexagon head and square head. See the national standard gb5780-gb5790, etc. ② Bolt for reaming hole: when in use, insert the bolt tightly into the reamed hole to prevent workpiece dislocation, see GB27, etc. ③ Anti rotation bolt: it can be divided into square neck and vertebral body, see gb12-15, etc. ④ Bolts for special purposes: for example, bolts for T-groove, see GB37; Union bolt, see gb798; Foundation bolts, see gb799, etc. ⑤ High strength bolt connection pair for steel structure: generally used for friction type connection of steel structures such as buildings, bridges, towers, pipe supports and hoisting machinery, see gb3632, etc. ⑵ nut: ① General purpose nuts: mainly refer to hexagonal nuts, and square nuts. There are many varieties, see gb41, gb6170-6177, etc. ② Slotted nut: it mainly refers to hexagon slotted nut, that is, the screw is processed above the hexagon nut. It is used in conjunction with threaded bolts with holes and cotter pins to prevent the relative rotation of bolts and nuts. See gb6178-6181, etc. ③ Lock nut: refers to the nut with locking function, including nylon insert hexagon lock nut, see gb889, gb6182, gb6183 and all metal hexagon lock nut, see gb6184-6187. ④ Nuts for special purposes: such as dished nuts, see gb62; Ring nut, see gb63; Cap nut, see gb802, gb923; Knurled nuts, see gb806, gb807 and embedded nuts, see gb809, etc. (3) screw: ① Machine screw: it is divided into many varieties due to different head types and groove types. The head types include cylindrical head, pan head, countersunk head and semi countersunk head. The head shape is slotted (slotted) and cross recessed. See gb65, gb67-69, gb818-820, etc. ② Set screw: the set screw uses its tail end to prevent mutual displacement between workpieces and transmit less torque. See gb71, gb73-75, gb77, gb78, etc. ③ Socket head cap screws: socket head cap screws are suitable for occasions where the installation space is small or the screw head needs to be embedded., See gb70, gb6190, gb6191 and gb2672-2674, etc. ④ Special purpose screws: such as set screws, see gb72, gb828, gb829; See gb827-839, gb948, gb948 and eyebolt, see gb825, etc. for screws that do not come out. (4) studs: ① Unequal length double head studs: applicable to the occasion where one end is screwed into the body of the component for connection or fastening. See gb897-900, etc. ② Equal length double head stud: it is suitable for matching the connecting end with the nut, and plays the role of connection or spacing. See gb901, gb953, etc. (5) washer: ① Flat washer: used to overcome the uneven supporting surface of the workpiece and increase the stress area of the supporting surface. See gb848, gb95-97 and gb5287. ② Spring (elastic) washer: see gb93, gb859, etc. for spring washer, see gb860, gb955, etc. ③ Non return washer: with internal tooth lock washer, see GB861; External tooth lock washer, see gb862; Single lug lock washer, see gb854; Double lug lock washer, see gb855; Round nut lock washer, see gb858, etc. ④ Inclined washer: in order to adapt to the inclination of the supporting surface of the workpiece, inclined washer can be used. Square bevel washer with I-steel, see gb852; Refer to gb853 for square and oblique washers for channel steel. (6) self tapping screw: ① Ordinary self tapping screw: the thread conforms to gb5280 (thread for self tapping screw), and the pitch is large, which is suitable for use on steel sheet, copper, aluminum and plastic. See gb845-847, gb5282-5284, etc. ② Self tapping locking screw: the thread conforms to ordinary metric coarse thread, which is suitable for use in vibration resistant occasions. See gb6560-6564. (7) rivet: ① Hot forged rivet: generally larger in size, it is mostly used in locomotives, ships, boilers, etc., and the head is usually formed by hot forging. See gb863-866. ② Cold heading forming rivet: generally, the diameter specification is ≤ 16mm, and the head is usually formed by cold heading. See gb867-870, gb109, etc. ③ Hollow and semi hollow rivets: hollow rivets, see gb976; Semi hollow rivet, see gb873-875, etc. ④ Special purpose rivets: headless rivets, see gb1016; Tubular rivet, see gb975; Label rivet, see gb827, etc. ⑤ Blind rivets: they are single-sided rivets. They are a new type of rivets widely used in recent years. They are fast, safe and convenient, and have the advantages of waterproof and leakage proof. (8) pin: ① Cylindrical pin: whether there is threaded cylindrical pin, see gb119; Internal thread cylindrical pin, see gb120; External thread cylindrical pin, see gb878; Elastic cylindrical pin, see gb879; Cylindrical pin with hole, see gb880, etc. ② Taper pin: with or without threaded cylindrical pin, see gb117; Internal thread cylindrical pin, see GB118; Screw tail taper pin, see gb881; Split taper pin, see gb877. ③ Cotter pin: generally, it matches with the threaded bolt with hole and slotted nut to prevent the bolt and nut from loosening. See gb91. (9) retaining ring: ① Circlip: circlip with holes. See GB893; Circlip for shaft. See gb894 and split ring for shaft gb896. ② Steel wire retainer: steel wire retainer for holes, see gb895.1; See gb895.2 for steel wire retaining ring for shaft and gb921 for steel wire locking ring. ③ Locking ring for shaft parts: see gb883 for the ring locked with taper pin; See gb884, gb885, etc. for the retaining ring locked with screws. ④ Shaft end retaining ring: see gb891 for shaft end retaining ring fastened with screws and gb892 for shaft end retaining ring fastened with bolts. (10) wood screw: It is divided into many varieties due to different head types and groove types. The head types include round head, countersunk head, semi countersunk head, etc. the head groove shape is slotted (slotted groove) and cross groove. See gb99-101, gb950-952, etc.

When bolts and nuts are used for fastening, the following standards must be followed. When assembling mechanical parts, there are many operations to tighten threads. In the fastening operation, tools play an important role. Only by using the most suitable tools correctly can we carry out the correct operation, which can not only form the best mechanical function, but also improve the operation efficiency. If improper tools are used or wrong methods are adopted, the operation will not only be incorrect and inefficient, but also cause injury or damage to products and tools. There are many kinds of fastening tools. Here are the most commonly used tools to explain their basic operations and the basic matters of the construction methods of fastening and loosening operations. 1. Ordinary fastening operation The ordinary fastening operation specified here refers to the operation of simply fastening without torque limitation when using wrenches and other fastening tools for fastening mechanical parts through bolts, nuts, washers, etc. 1) Wrench When using a fixed caliber wrench, it is very important to use a tool that conforms to the size of the bolt or nut of the working object. If it is too large, the bolt head will be deformed and the wrench cannot be clamped. In addition, the length of the wrench is determined according to the force applied to the wrench, so methods such as connecting the extended handle and superimposing with another wrench to apply a greater force cannot be used.

Development status of global fastener industry The global industrial fastener market is expected to grow from USD 84.9 billion in 2016 to USD 116.5 billion in 2022, with an average annual compound growth rate of 5.42%. In recent years, with the economic and industrial development of China, the United States, Russia, Brazil, Poland and India, it will further drive the growth of fastener demand. In addition, the growth of household appliances, automobile industry, aerospace manufacturing, construction industry, electronic industry, mechanical equipment manufacturing and manufacturing after-sales market will also stimulate the rise of fastener market demand. The United States, Germany, Britain, France, Japan and Italy are importers of fasteners and exporters of high-quality fasteners. In terms of product standards, the United States, Japan and other manufacturing developed countries started their development early and the industry standards are perfect. There are certain technical advantages in fastener production.

Measures to improve the strength of bolt connection The strength of bolted connection mainly depends on the strength of bolts. There are many factors that affect the strength of bolts, such as structure, size parameters, assembly process, materials, manufacturing accuracy grade, etc. 1. Improve the fatigue strength of bolts Theory and practice have proved that under the condition of constant working load and residual preload, reducing the bolt stiffness or increasing the stiffness of the connected part can improve the fatigue strength of the bolt, but the preload should be appropriately increased to ensure the tightness of the connection. The common measures to reduce the bolt stiffness are: appropriately increasing the bolt length, reducing the bolt rod diameter or making a hollow structure - Flexible bolt. The flexible bolt has large deformation and strong energy absorption when under stress, and is also suitable for bearing impact and vibration. The elastic element is installed under the nut. When the working load is transmitted from the connected part, it can also play the effect of flexible bolt due to the large deformation of the elastic element. In order to increase the stiffness of the connected parts, it is not suitable to use gaskets with small stiffness. Sealing ring is preferred for tight connection. 2. Improving load distribution between threads When an ordinary nut is used, the axial load is unevenly distributed among the turns of the screw thread, as shown in figure 9-39 of the textbook. From the bearing surface of the nut, the load on the first turn is the largest, and then each turn decreases. Theoretical analysis and experiments show that the more the number of turns, the more significant the uneven load distribution, and the threads after the 8th to 10th turns are almost free of load. Therefore, the use of thick nuts with a large number of turns can not improve the connection strength. If the mounting (tension) nut as shown in figure 9-41 is used, both the conical mounting section of the nut and the bolt rod are subject to tensile deformation, which helps to reduce the difference in pitch between the nut and the bolt rod, so as to make the load distribution more uniform. 3. Reduce stress concentration There is stress concentration at the root and end of the thread, and at the joint between the bolt head and the bolt rod, which is a dangerous position for fracture: especially at the root of the screw thread, the tooth is subject to bending shear due to the stretching of the bolt rod, and the stress is uneven, which is more serious. The fatigue strength of bolts can be increased by 20%~40% by properly increasing the root fillet radius to reduce stress concentration; Good results have been achieved by using a tool withdrawal groove at the end of the thread and by retaining threads in the bolt rod within the pressure bearing surface of the nut. The newly developed MJ bolts are used for aviation and spacecraft bolts. Its main structural feature is that the root fillet radius is increased. High strength steel bolts are sensitive to stress concentration, but the results are favorable because they can be tightened with greater preload and higher ultimate strength. 4. Adopt reasonable manufacturing process The manufacturing process has a great influence on the fatigue strength of bolts. When the milled thread is used, due to the effect of cold work hardening, there is residual compressive stress on the surface, the metal streamline is reasonable, and the fatigue strength of the bolt can be 30%~40% higher than that of the turned thread; The effect of rolling after heat treatment is better. In addition, carbonitriding, nitriding and shot peening can improve the fatigue strength of bolts.

As most industries saw significant cost increases throughout 2021, many of our customers are wondering what the cost landscape looks like for 2022, especially as it relates to fasteners. Although fasteners typically make up a small portion of a product`s or project`s overall cost, fasteners are not immune to price fluctuation, and it`s wise of fastener buyers to keep this in mind. The cost of fasteners is 2022 is going to be driven by several factors; the ongoing coronavirus pandemic and how its affects will impact production levels, the cost of raw materials, the cost of shipping and delivery, and the overall demand for fasteners both domestically and around the world. Globally, the cost of raw materials will remain high in 2022 as demand continues to climb. At the beginning of the pandemic, plants slowed down or halted completely; fearing a worldwide recession. Thankfully, that fear was unfounded and demand did not disappear, instead it shifted from sectors like air travel, to consumer goods and vehicles. While the commodities industries work to replenish their supply, demand will continue to drive cost. Production is expected to rebound in the early half of 2022, but we know that COVID disruptions can stall production and capacity without warning. Another factor that could affect input is the curbing of industrial production in China due to the 2022 Winter Olympics. China is where a large share of the world`s fasteners are manufactured, and they often forcefully slow down production to improve air quality prior to and during major events. Since the beginning of the pandemic,has spiked by as much as three or four times the pre-COVID price. As the global demand continues to outpace available capacity, the price of overseas shipping will continue to affect fastener prices. Typically, containers have a peak season for goods, usually from July to October, but this year volumes increased and then remained elevated, causing available capacity to be maxed out, according to Judah Levine, research lead at Freightos. Rates were already rising for overseas shipping when a COVID outbreak at the port of Yantian, one of China`s busiest container ports, added even lengthier delays. Efforts to restock empty warehouses are likely to keep demand elevated beyond the peak season. Road, bridge, pipe, electric wire and rail projects will require an enormous amount of approximately $550 billion steel, aluminum and copper. The US federal government has slated towards these projects, creating even more demand for metals. Other building materials, such as cement and lumber, could also be used for construction projects under the bill. Fasteners will be used in almost all of these projects, and adding in the rebound in manufacturing, fastener demand will remain quite high throughout the new year. While we can`t tell exactly how much fastener prices may rise, we`re fairly sure they won`t be decreasing any time soon. If you`re planning your fastener purchases for 2022 now, contact Mudge Fasteners at (800) 634-0406 now to learn how you can get ahead of any additional price increases and stay profitable in the new year.

What are fasteners? What is the main purpose of fasteners Fastener is a kind of mechanical part widely used for fastening and connection. It is characterized by various varieties and specifications, different performance and uses, and high degree of standardization, serialization and universality. Therefore, some people also call a type of fastener in the standard standard fastener, which is called standard fastener for short. What are the main uses of fasteners: Fasteners are mainly used in energy, electronics, electrical appliances, machinery, chemical industry, metallurgy, mold, hydraulic and other fields. There are various fasteners on all kinds of machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, chemicals, instruments and supplies. Fasteners are also known as the most widely used mechanical basic parts. Introduction to fasteners: Fasteners include: bolts, studs, screws, nuts, washers and pins. Fasteners made of stainless steel, aluminum alloy and titanium alloy will lock or bite. The fasteners themselves have corrosion resistance and form a thin oxide layer on the metal surface to prevent further corrosion when the surface is damaged. When the stainless steel is locked, the heat between the teeth will be cut off or the metal locking layer will be blocked, resulting in the destruction of the locking layer. When this happens, the stainless steel fasteners are fully locked and can never be removed or locked. This blocking shear bonding locking sequence usually occurs within a few seconds, so we should correctly understand this kind of fastener when using it, so that this phenomenon can be prevented.

Fasteners are the most widely used mechanical foundations. China`s fastener products are exported to many countries globally, and fastener products from all over the world are also pouring into the Chinese market. Fasteners, as one of the products with the most significant import and export volume in China, are in line with international standards, which have important practical significance and practical significance for promoting Chinese fastener enterprises to go to the world and promoting fastener enterprises to participate in international cooperation and competition fully. Strategic significance. Due to the specifications, dimensions, tolerances, weights, properties, surface conditions, marking methods, and specific requirements of items such as acceptance inspection, marking, and packaging for each specific fastener product. From January 2020 to January 2021, the export value of China`s fasteners increased steadily. In 2020, the export value was 8.8 billion US dollars. In January 2021, the export value was 870 million US dollars, a year-on-year increase of 74%. From January 2020 to January 2021, China`s export volume of fasteners increased steadily. In 2020, the export volume was 4.07 million tons, and in January 2021, the export volume was 410,000 tons, a year-on-year increase of 56%. There are about 10.000 fastener manufacturers in China, of which there are nearly 2.000 large-scale fastener enterprises. There are too many small and medium-sized fastener enterprises, insufficient technology, and high investment in replacing advanced equipment, so it is impossible to produce high-quality and high-quality fasteners-technology Products. The development of the industry is seriously unbalanced, and it is in urgent need of transformation and upgrading to develop towards the overall high-end direction.With the rapid development of modern technology, the fastener industry also improved in 2019. For example, foremost standard parts industry leaders have entered the field of e-commerce to meet the needs of the times. With the penetration of Internet technology in the industry, fasteners are constantly increasing. Update new platform, a new way out. There are about 7,000 fastener manufacturers in China, and there are more than 2,000 enterprises above designated size in this industry. Still, there are few large-scale enterprises with a total industrial output value of more than 500 million yuan. Therefore, the overall scale of domestic fastener enterprises is relatively small.

Hex head bolts are versatile and adaptable fasteners, making them suitable for a variety of uses across a range of industries and applications. Example hex bolt uses include hex head screws for wood, metal, and many other environments and scenarios. They offer strong tensile properties and most standard types can be used in multiple locations (dependent upon the material and finish). As a result, hex bolts are a widely used staple fastener. Their primary use is for heavy-duty fixing and fastening applications. This could include: Within construction projects During the erection, repair, and maintenance of buildings, bridges, and road infrastructure Machinery assemblies Woodworking tasks such as fastening frames Engineering applications Vehicle and automotive