1. China Nut's welding technology process: work preparation → joint assembly → installation of temporary bolts → installation of high-strength bolts → tightening of high-strength bolts → inspection and inspection.
2. Preparation for welding of finish-rolled nuts: prepare wrenches, temporary bolts, overshoots, wire brushes, etc. The first thing to do is to check the construction torque, that is, to check the torque wrench used, it is necessary to check before the class, and only after the torque is checked Quasi-use. The torque calibration corresponds to a designated person. The length of the hexagonal finish-rolled nut is selected, considering that the steel used in the processing of steel components is usually normal service. Sometimes the material substitutes are mostly large instead of small, and thick instead of thin. Therefore, the total thickness of the connection is increased by 3 to 4 mm. Many, therefore, the length of high-strength bolts and nuts should be selected, usually 2 to 3 buckles should be grown after tightening, and then a set of spare parts should be equipped according to the request.
3. Assembling of Bolt Factory's finishing-rolled nuts: sort out the conflicting surface. If the plate is not flat, it should be assembled after the flatness meets the requirements. There should be no paint or sludge on the conflict surface, and there should be no burrs around the hole. The conflict surface should be cleaned with a wire brush, and the brush direction should be perpendicular to the direction of the conflict force. When in doubt about the installation hole, do not use oxygen-acetylene to ream the hole. Use a reaming drill to ream the hole. After reaming, rearrange the burrs around the hole.

       How can I purchase high-quality China Nut?

　　 1. Measure the outer diameter, the defective product is thin and short, obviously thinner than the national standard screw. Even more surprising is that the defective product does not even have a tension spring washer on the screw. Tension spring washers are mainly used for compression. The expansion screw of the tension spring washer is not easy to fix firmly.
　　
　　2. From the outside, the micro screw manufacturer introduced that the original screw has been treated with appearance, high gloss, and lubricated without sand holes. However, defective screws have rough processing, shallow threads, burrs, different screw angle widths, too shallow thread grooves, and uneven threads. If such a defective screw is used in furniture, it is very simple to slide or even break, which is basically a "disposable product".
　　
　　3. Check the certificate of origin of Bolt Factory's products. Since there are supporting manufacturers of export products, the requirements for production and quality are stricter, and the quality is guaranteed.

China Nut is mainly used in steel structure engineering. It is used to connect the connection points of steel structure steel plates. Iron will rust, but steel structure bolts are not easy to rust. However, it is difficult to avoid rust in some special environments. This problem, for example, after being corroded by natural weather in a long-term humid environment at the seaside, it may cause rust problems. If this problem can be solved, it is only necessary to replace it. If steel structural bolts are exposed to rain or some kind of liquid, they will cause rust. Corrosion such as bird droppings in places with abundant seawater in the wild is the cause of rusting of steel structural bolts. In order to solve this problem, we must take corresponding actions and take moisture-proof measures for the steel structure bolts.

　　There is still a way to prevent moisture. Solvent-free paint can be used. Here, dipping paint without oxidizing components, such as epoxy urethane or undenatured epoxy-based dipping paint.

The use of these paints by Bolt Factory can effectively protect the anchor bolts of the steel structure. It has a good isolation and reuse for isolating water vapor in the air. The main steel structure bolts do not oxidize and rust, and the hardness performance of the steel can be guaranteed. No loss, so as to ensure the fastness of the anchor bolts and the safety of the corresponding equipment.

Do you know what processes are available for metal heat treatment? Today Bolt Factory-Zhejiang Weigao will explain the three major processes of metal heat treatment.
Metal heat treatment processes can be roughly divided into three categories: overall heat treatment, surface heat treatment and chemical heat treatment. According to the different heating medium, heating temperature and cooling method, each category can be divided into several different heat treatment processes. The same metal uses different heat treatment processes to obtain different structures and thus have different properties. Steel is the most widely used metal in industry, and the microstructure of steel is also the most complicated, so there are many types of steel heat treatment processes.

Overall heat treatment
It is a metal heat treatment process that heats the workpiece as a whole and then cools it at an appropriate speed to change its overall mechanical properties. The overall heat treatment of steel has four basic processes: annealing, normalizing, quenching and tempering. Annealing, normalizing, quenching, and tempering are the "four fires" in the overall heat treatment. Quenching and tempering are closely related, and they are often used in conjunction with one another.
Annealing is to heat the workpiece to an appropriate temperature, use different holding times according to the material and workpiece size, and then slowly cool it, the purpose is to make the internal structure of the metal reach or close to the equilibrium state, obtain good process performance and use performance, or for further quenching Prepare for organization.
Normalizing is to heat the workpiece to a suitable temperature and then cool it in the air. The effect of normalizing is similar to annealing, except that the resulting structure is finer. It is often used to improve the cutting performance of low-carbon materials, and sometimes it is used for some low-carbon materials As the final heat treatment.
Quenching is the rapid cooling of the workpiece in quenching medium such as water, oil or other inorganic salts, organic aqueous solutions after heating and holding the workpiece. After quenching, the steel becomes hard, but at the same time it becomes brittle.
Tempering: In order to reduce the brittleness of steel parts, the quenched steel parts are kept for a long time at an appropriate temperature higher than room temperature but lower than 650℃, and then cooled.
The "Four Fires" have evolved different heat treatment processes with different heating temperatures and cooling methods. In order to obtain a certain strength and toughness, the process of combining quenching and high temperature tempering is called quenching and tempering. After some alloys are quenched to form a supersaturated solid solution, they are kept at room temperature or a slightly higher temperature for a longer period of time to improve the hardness, strength, or electrical magnetic properties of the alloy. Such a heat treatment process is called aging treatment.
The method of effectively and closely combining pressure processing deformation and heat treatment to obtain a good strength and toughness of the workpiece is called thermomechanical treatment; heat treatment performed in a negative pressure atmosphere or in a vacuum is called vacuum heat treatment, which can not only make The workpiece is not oxidized or decarburized. It keeps the surface of the workpiece smooth and clean after treatment, improves the performance of the workpiece, and can also pass through the infiltration agent for chemical heat treatment.
Surface heat treatment
A metal heat treatment process that only heats the surface of the workpiece to change the mechanical properties of the surface. In order to heat only the surface of the workpiece without causing excessive heat to be transferred into the interior of the workpiece, the heat source used must have a high energy density, that is, to give a larger heat energy to the workpiece per unit area, so that the surface or part of the workpiece can be short-term or instantaneous Reach high temperatures. The main methods of surface heat treatment include flame quenching and induction heating heat treatment. Commonly used heat sources include flames such as oxygen acetylene or oxypropane, induction current, laser, and electron beam.
Chemical heat treatment
Metal heat treatment process by changing the chemical composition, organization and performance of the workpiece surface. The difference between chemical heat treatment and surface heat treatment is that the latter changes the chemical composition of the surface of the workpiece. Chemical heat treatment is to heat the workpiece in a medium (gas, liquid, solid) containing carbon, nitrogen or other alloying elements for a long time, so that the surface of the workpiece is infiltrated with elements such as carbon, nitrogen, boron and chromium. After infiltration of elements, other heat treatment processes such as quenching and tempering are sometimes required. The main methods of chemical heat treatment are carburizing, nitriding and metalizing.
Conclusion
Heat treatment is one of the important processes in the manufacturing process of China Nut and molds. It can control various properties of the workpiece, such as wear resistance, corrosion resistance, and magnetic properties. It can also improve the structure and stress state of the blank to facilitate various cold and hot processing. For example, white cast iron can obtain malleable cast iron after long time annealing treatment, which can improve plasticity; gears adopt correct heat treatment process, and the service life can be doubled or dozens of times longer than gears without heat treatment; in addition, cheap carbon steel can be penetrated Certain alloying elements have certain properties of expensive alloy steels, which can replace certain heat-resistant steels and stainless steels; almost all tools and molds require heat treatment before they can be used.

   1. From the perspective of raw materials: China Stud Supplier's high-strength bolts and nuts are made of high-strength materials.
  2. From the perspective of intensity level: it is increasingly widely used. Two strength levels of 8.8s and 10.9s are commonly used.
  3. From the point of view of the force characteristics of Industrial Bolt Factory: applying pre-tension and transferring external force by friction. Ordinary bolted connections rely on bolt shear resistance and hole wall pressure to transmit shear force. Its influence can be ignored. In addition to its high material strength, high-strength bolts and nuts also exert a large pretension on the bolts, which causes squeezing force between the connecting members, so that there is a large friction force perpendicular to the screw. Moreover, the pre-tension, anti-slip coefficient and steel type directly affect its bearing capacity.

I believe you have a certain understanding of fasteners, but you may not know so much about the threads of fasteners. The following is the use and classification of fastener threads. Let’s take a look with China Stud Supplier.

       Threads are used in a wide range of applications, from airplanes and automobiles to water pipes and gas used in our daily lives. Most threads play a role in fastening connections, followed by the transmission of force and motion. There are also some special-purpose threads. Although there are many types, the number is limited. The durability of the thread is due to its simple structure, reliable performance, convenient disassembly, and ease of manufacture, making it an indispensable structural element in various electromechanical products today. According to the purpose of the thread, all kinds of threaded parts should have the following two basic functions: one is good screwability; the other is sufficient strength.
       The threads of Industrial Bolt Factory can be divided into: metric thread (metric thread), inch thread, American thread, etc. according to the region (country). We are used to refer to the inch thread and the American thread collectively as the inch thread, and its profile angle is 60°, 55°, etc., the related thread parameters such as diameter and pitch adopt inch size (inch). In our country, the tooth profile angle is unified to 60°, and the diameter and pitch series in millimeters (mm) are used to name this type of thread: ordinary thread. The above is the basic knowledge of fastener threads introduced by the editor today, I hope it will be helpful to everyone. Our company will serve you wholeheartedly, waiting for your call or visit at any time.

        What are the surface treatment amplification of standard parts? It is not unknown to people in this industry. Today zhejiang weigao Industrial Bolt Factory will give you a brief introduction to the surface treatment methods of standard parts:

       1. Electroplating of standard parts

       Standard part plating refers to immersing parts of fasteners that need to be plated into a specific aqueous solution. The aqueous solution will contain some deposited metal compounds. In this way, after passing current through the aqueous solution, the metal substances in the solution will precipitate out and adhere to the tight The immersion part of the firmware. The electroplating of standard parts generally includes zinc plating, copper, nickel, chromium, copper-nickel alloy, etc.

       2. Hot dip galvanizing of standard parts

       The hot dip galvanizing of the standard parts is to immerse the standard parts of carbon steel components into the molten zinc plating bath with a heat of about 510°C, so that the iron-zinc alloy on the surface of the standard parts will be converted into passivated zinc to obtain surface treatment effect. The price of hot dip galvanizing for standard parts is higher than that of electroplating.

       3. Mechanical plating of standard parts

       The mechanical plating of standard parts refers to the use of specific physical and chemical means to impact the surface of the fastener with the powder of the coated metal, so that the coated metal forms a coating on the surface of the fastener by cold welding to achieve surface treatment effect. The mechanical plating of standard parts is mainly suitable for spare parts such as screws, nuts and washers.

       The main purpose of the surface treatment of China Stud Supplier standard parts is to make the fastener itself obtain anti-corrosion ability to increase the reliability and adaptability of the standard parts. Therefore, the quality judgment of the surface treatment of the standard parts is mainly to check Whether the anti-corrosion ability of standard parts is effectively increased, and whether the increase is in line with the expected requirements.

1. Application of Industrial Bolt Factory's steel structure bolts
  Steel structure bolts are mainly used for steel structure engineering, and are used to connect the connection points of steel structure steel plates. Steel structural bolts are high-strength bolts and standard components. Better fastening performance, used in steel structure and engineering to achieve the fastening effect. In the general steel structure, the required steel structure bolts are all above 8.8, there are 10.9 and 12.9, which are high-strength steel structure bolts. Sometimes the bolts on the steel structure do not need to be plated.
  Second, steel structure bolt classification
  Steel structure bolts are divided into torsion-shear high-strength bolts and large hexagon high-strength bolts.The large hexagon high-strength bolts belong to the high-strength level of ordinary screws, while the torsion-shear high-strength bolts are improved types of large hexagon high-strength bolts for better construction.
  Three, steel structure bolt construction
The construction of the steel structure bolts must be tightened first and then the final tightening.The initial tightening steel structure bolts need to use impact type electric wrench or torque adjustable electric wrench; while the final tightening steel structure bolts have strict requirements, the final tightening torsion shear type steel structural bolts must Use torsional shear type electric wrench, and the final tightening torque type steel structure bolt must use torque type electric wrench

  Characteristics of steel structure
  Steel structure system has comprehensive advantages such as light weight, factory manufacturing, fast installation, short construction period, good seismic performance, fast investment recovery, less environmental pollution, and high degree of industrialization. Compared with reinforced concrete structure, it has more unique advantages. Globally, especially in developed countries and regions, steel structures are widely used in various engineering constructions, such as steel bridges, steel workshops, steel gates, various large pipeline containers, high-rise buildings and tower rail mechanisms.
  Technical process of steel structure installation
   1. According to the normal installation sequence and process requirements, prefabricating and assembling the steel structure on the steel platform must ensure the quality of welding.
  2. The distance between the splice flange joints of the profiled steel and the splice joints of the web should be greater than 200mm. Flange panel splice length cannot be less than 2 times the width of the plate; web splice width should not be less than 300mm, and the length should not be less than 600mm.
  3. In order to facilitate the welding and ensure the welding quality, as far as possible, the stiffener plates, connecting plates, backing plates, beams, etc. on the pillars, beams, etc. are grouped and welded on the ground steel platform according to the construction drawing size.
  4. In addition to the fabrication and assembly of steel components prefabricated on the steel platform by China Stud Supplier in accordance with the construction drawings and specifications, it is also necessary to consider the changes in on-site installation processability and installation dimensions.

People who often deal with hardware know that fasteners often appear locked during use. Locking fasteners will cause the operation of the fastener itself to be ineffective, that is, it cannot be disassembled or continued to be fastened. Pieces. What causes this to cause the fasteners to lock up? How can I avoid the state of the fasteners locking up? China Stud Supplier - Zhejiang Weigao Standard Parts Co., Ltd. .
　　 1. Reasons for fastener locking
The locking of fasteners generally occurs on products made of stainless steel or alloy materials.This is because these metal materials themselves have the ability to prevent corrosion.Once the metal surface of the fastener is damaged, it will appear to oxidize. Layer to provide protection against the intensification of rust, but when the fastener is locked, the pressure and heat generated by the force will destroy the oxide layer, causing blocking or shearing between the metal threads, and then the phenomenon of adhesion, also It is deadlocked.
　　 2. The method of fasteners to avoid locking:
　　 The locking of the fasteners cannot be completely eliminated, but we can reduce the chance of locking by paying attention to various factors, such as ensuring the load capacity of the fasteners and choosing screws and nuts with more tensile strength.
Whether the thread of the fastener is clean also has a certain effect on whether it locks up.When the thread is rough or unclean, lockup occurs more often, so be sure to clean the fastener and remove iron debris or Dirt.
　　Industrial Bolt Factory's fasteners must be lubricated, but the consequences are very serious. The heat generated by the force on the metal parts will be effectively reduced. This is because it can reduce the locking of the fasteners.

Industrial Bolt does not tighten tightly and keeps slipping. If such a problem occurs, Industrial Bolt Factory can be solved by the following methods:

1. See if the male wire is still slippery, add an aluminum sheet

2. You can flatten the Industrial Bolt. If possible, replace the Industrial Bolt with stainless steel. If it is plastic, it is better to see what material is mainly screwed. For example, if it is wood, add a small wooden strip (toothpick) to the hole. If it is iron

3. Go find some raw material tape, then wrap it around the plastic Industrial Bolt, and then twist it.

4.Industrial Bolt sliding wire can only be changed to Industrial Bolt. If you can’t control it, just cut a little bit of iron in the screw hole and cut it into a long bar. Don’t be too thick and thin (the can can be inside the Wanglaoji). Insert it into the screw hole and screw it. When Industrial Bolt is going to the end, it will slowly twist its own car repair wire. This can be done as long as the force is not too large.

Zhejiang Wego China Stud Supplier is constantly updating its expertise in this area, and we welcome all interested customers to leave us a message.

       According to the development situation, the global Fasteners Suppliers has entered a period of micro-growth, and China is no exception. At present, the global demand for fasteners is mainly concentrated in the three major markets of North America, Western Europe and Asia. Its annual demand is more than 10 billion US dollars, which is also the main market for domestic fastener exports.
       After many years of maintaining a double-digit growth trend, the global fastener industry experienced negative growth last year. At the same time, due to the tightening of the traditional European and American markets, this downward trend shows no signs of ending.
       In order to maintain the continuous and stable development of the fastener industry, the domestic fastener industry has put forward a new idea of ​​"adjusting during development and improving during adjustment", adhering to market structure and product structure adjustment as the starting point, and promoting corporate restructuring and industry Agglomeration promotes the transformation of the economic growth pattern of the entire industry. After continuous efforts in the past, my country's fastener industry has maintained steady growth, the pace of industrial adjustment has accelerated, and there have been new breakthroughs in restructuring and industrial concentration.
       Although my country's fastener industry suffered a setback in 2012, the industry is expected to grow steadily in 2013. It is estimated that by 2013 fastener production and sales will reach approximately 7.3 million tons. With the growth of China-ASEAN Free Trade Area, more potential free trade areas may emerge, and the efforts of Chinese enterprises to go out, China's fastener export market is expected to be further diversified, especially in emerging markets and developing National expansion.
       Relevant experts pointed out that under the conditions of contemporary socialist market economy, fastener companies should pay attention to, rely on the state's support policies for the industry, and grasp the direction of the industry. . Fastener enterprises should learn to think and fully understand the industrial policy and guidance of the entire country, and seize the opportunity to carry out technological transformation.
       For domestic Stud Manufacturer, there is no lack of opportunities to get rid of development bottlenecks, but the ability to seize opportunities. The demand for fasteners in the market is developing in the direction of high precision. Domestic manufacturers must greatly improve product performance in order to better grasp the pulse of the market.

Hexagon Socket Head Bolt is a fastener consisting of a head and screws (cylinders with external threads). It needs to cooperate with the nut to be used as a fastener to connect two parts with through holes. This form of connection is called a bolt connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a detachable connection. So what should we pay attention to before using?

Hexagon Socket Head Bolt introduction:

1. Correct product selection: Before use, please confirm whether the mechanical properties of the product meet the requirements for use, such as the tensile strength of the Hexagon Socket Head Bolt and the load of the nut. The length of the hexagon socket screws should be properly selected. After tightening, the selection should be based on the 1-2 pitch of the nut.

2. Before use, please check whether the thread is rough, and whether there is iron filings or dust between the threads. These things often lead to lockups.

3. Fasteners can be lubricated before use: it is recommended to use butter, molybdenum disulfide, mica, graphite or talc powder for lubrication. At present, it is generally lubricated with wax to prevent locking.

4. Pay attention to the method of use:

(1) The speed and strength of the screw-in are appropriate, not too fast or too large. Use torque wrenches or socket wrenches whenever possible. Prevent the use of adjustable wrenches or electric wrenches. Excessive speed will cause the temperature to rise rapidly and cause locking.

(2) The direction of the applied force, the nut must be tightened perpendicular to the axis of the screw.

5. The use of washers can effectively prevent the problem of over-tightening.

6. Fasteners made of stainless steel, aluminum alloy and titanium alloy often lock or bite. These metal alloys have corrosion resistance. When the surface is damaged, a thin oxide layer is formed on the metal surface to prevent further corrosion. When the stainless steel fasteners are locked, the pressure and heat generated between the teeth will destroy the oxide layer, resulting in blockage or shearing between the metal threads, and then adhesion. When this phenomenon continues to occur, the stainless steel fasteners will be completely locked and can no longer be removed or locked.

The above is China Custom Bolt Wholesaler——Zhejiang Weigao Standard Parts Co., Ltd. introduces the relevant knowledge of Hexagon Socket Head Bolt, hope to give you reference when choosing Hexagon Socket Head Bolt.

 Since the energy of arc burning during Hexagon Socket Head Bolt welding is concentrated between Hexagon Socket Head Bolt and the base metal and their melting zone, a certain pressure must be applied in the melting zone during Hexagon Socket Head Bolt welding. The pressure at this time is quickly and accurately obtained after the arc burns, and there is no pulsation. After a short welding time and peak current, under pressure, the end of the Hexagon Socket Head Bolt is immersed in the molten pool, and the liquid metal part is extruded out of the joint to form a welded joint, which makes the application of stud welding There are many characteristics.

Characteristics of stud welding machine

Very time and cost saving

  All stud welded structures do not require drilling, punching, threading, riveting, screwing and finishing.

2. The expanding application potential of structural design

  When the stud welding machine is used, the welding process is short time, large current and small penetration. Therefore, it can be welded to a very thin plate. For the use of ceramic ring drawn arc stud welding (stud welding machine) and short-cycle drawn arc welding, the plate thickness can be up to 1mm. Capacitor discharge arc stud welding can reach 0.6mm, while capacitor discharge tip ignition stud welding can reach 0.5mm.

  Stud welding workpieces must be welded from one side.

  It can be welded at all positions, and it can be welded to the restricted vertical partition by means of the expander.

  Because it is welded for a short time and rarely deforms after welding, no trimming is required.

  Stud welded joints can achieve high strength.

  After the plating or high alloy plate is welded, there is no mark on the back.

3. Good economy

  The advantage of stud welding over other welding methods lies in the welding power. For mass-produced workpieces, it can reach 8-40 pieces / min in a short welding time (3-980ms) (according to different diameter studs and different welding power). The automatic feeding stud welding machine can reach 60 pieces / min.

  Standard studs are low cost.

  There are many types of stud welding equipment and welding guns, and the equipment purchase cost is relatively low.

  Depending on the product, it can be made into a multi-station automatic welding machine, or a high-precision gantry CNC automatic welding machine.

  Stud welding has higher quality reproducibility and smaller scrap rate.

  However, the application of traditional Chinese medicine in stud welding is to note that stud welding, like other fusion welding, has restrictions on the carbon content of steel-for structural steel studs, the carbon content w (C) should be 0.18% Within; and the carbon content w (C) of the base metal should be within 0.2%.

  According to the different methods of stud welding, the recommended stud material and base metal combination are weldable: otherwise the stud and base metal will be insoluble with each other.

  The combination of stud material and base material beyond the recommended range shall be determined by experiment to determine the weldability and the possibility of relevant inspection and evaluation according to the design requirements of the product.

 As a professional China Custom Bolt Wholesaler, we bring high-quality products and perfect services to consumers in the market. If you happen to have this demand, then do n’t miss us, if you are interested Come and leave a message for us.

Many people think that stainless steel Hexagon Socket Head Bolt is a screw that will not rust, but in fact stainless steel Hexagon Socket Head Bolt is not necessarily not rusty, but relatively speaking, stainless steel Hexagon Socket Head Bolt is more resistant to corrosion and rust than iron screws Be stronger. However, under certain circumstances, the stainless steel Hexagon Socket Head Bolt will still rust. So what is the cause of the rust of the stainless steel Hexagon Socket Head Bolt? What causes rust? zhejiangweigao China Custom Bolt Wholesaler, I will give you a specific introduction in this regard.
Stainless steel Hexagon Socket Head Bolt has good characteristics, high temperature resistance, strong corrosion resistance, and certain rust resistance. However, it will rust even in harsh environments. Like in a very humid environment, the wind blows the sun, the rain blows the wind. Over time, there must be some rust. Or it may come into contact with some acid-base chemicals and produce a chemical reaction, which may lead to corrosion and rust. There are some Hexagon Socket Head Bolts of stainless steel that are not suitable for a specific occasion. Like the material is stainless steel SUS201 Hexagon Socket Head Bolt, it is not suitable for use at sea because the seawater is salty and used in the sea. Time immersion in seawater will cause corrosion and rust. Therefore, if it is used in marine products, it is generally not recommended to use stainless steel SUS316.
It is not difficult to conclude from the above that the stainless steel Hexagon Socket Head Bolt will corrode and rust under certain conditions. This requires us to use stainless steel Hexagon Socket Head Bolt properly, and use it reasonably. Under different conditions, use different materials of stainless steel Hexagon Socket Head Bolt. In different occasions, when using stainless steel Hexagon Socket Head Bolt, pay special attention to the details, try to control the corrosion and rust of stainless steel Hexagon Socket Head Bolt.
The above is the non-standard stainless steel screw manufacturer-Jin Shengtai explained to you about whether the stainless steel Hexagon Socket Head Bolt will corrode and rust. I hope it will help you.

What are the characteristics of the appearance of roof bolts?  Next, Zhejiang Weigao Bolt Factory will introduce you in detail:
1. According to the stress mode of connection, there are common bolts and bolts for reaming holes. Bolts for reaming holes shall be matched with the size of holes and used when subjected to transverse force.
2, according to the shape of the head has a hexagonal head, round head, square head, countersunk head, etc. Generally countersunk head is used in the place where smooth surface is not protruding after connection, because the countersunk head can be screwed into the parts.

In addition, in order to meet the need of locking after installation, there are holes in the head and in the rod, which can prevent the bolts from loosening when subjected to vibration.
Some China Nut need to be made into thin smooth rods without threads, which are called thin waist bolts. These bolts are beneficial to the connection under variable forces.
There are special high-strength bolts on the steel structure. The head will be bigger. The size will also change.

In addition, there are special uses: T-groove bolts are used most frequently on machine tools and jigs, with special shapes. Both sides of the head must be cut off. Anchor bolts are used for connecting and fixing machines and the ground, and there are many shapes. U-shaped bolts, as mentioned above. etc.

There is also a special stud for welding, one end of which is threaded and the other end is not, which can be welded to the part while the other end is directly screwed with the nut.

Large hexagonal bolts are usually used in steel structures with two flat pads and high strength nuts.  Torsional shear high strength bolt pairs are also used in steel structures.  The strength grade is 10.9.  It is mainly used to connect power facilities and large steel structure products.  The nominal tensile strength of the big hexagonal bolt material reaches 400MPa grade;  The yield ratio value of the big hexagonal bolt material is 0.6;  The nominal yield strength of large hexagonal bolt material reaches 400×0.6=240MPa grade performance grade 10.9 grade high strength bolt.

The hexagon head of the large hexagon bolt is different from that of the general outer hexagon bolt.  The hexagon head size of large hexagon bolt is larger than that of ordinary hexagon bolt, so large hexagon bolt can also be called large hexagon bolt.

Zhejiang Weigao Standard Parts Company's raw materials for producing large hexagonal bolts are all high-quality steel products produced by domestic well-known large-scale iron and steel production enterprises in accordance with relevant material standards, and are manufactured and processed by international advanced professional production equipment.  Advanced heat treatment production line is adopted.  All production links are strictly controlled by the quality inspection department.  On-site inspection will eliminate the occurrence of unqualified products from the source to ensure that the performance index of each large hexagon bolt fully meets the product standard.  Our company is an ISO 9001 international quality management system certification enterprise. Our factory has complete testing equipment, strict quality control standards and strict quality inspection of finished products.  The large hexagonal bolts produced by our company are excellent in material selection, stable in quality, strict in inspection, reasonable in price, and provide product quality inspection certificates.  As a trustworthy China Custom Bolt Wholesaler, we can provide you with more comprehensive support and protection. We also welcome all interested customers to leave us a message.

The most important link in the development and design of Industrial Nut is quality control.  There are several main doors from feeding to finished product delivery, and these doors have different inspection methods.  First of all, feed is related to appearance, size, composition, performance, detection of harmful substances, etc.  This process is more about appearance, size, impact experiment and forging streamline.  Heat treatment is more about appearance, hardness, torque, tension and gold etc.  Surface treatment is more about hydrogen embrittlement test, coating, salt spray, etc.  , including testing of hazardous substances shipped.
In terms of size and appearance detection, secondary size, profile measuring instrument, three-coordinate measuring instrument and image sorting machine are commonly used (this is a full selection machine);
In mechanical and chemical tests, there are mainly hardness machines (Lloyd's and Vickers), tensile machines and metallographic microscopes.
Industrial nuts have spectrum analyzer and salt spray tester for material testing.