What problems are prone to occur during the use of Dacromet bolts?

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When people use Dacromet bolts, there will always be problems of one kind or another. Let’s analyze together what causes such problems.

1. Material reasons:

The threads of Dacromet bolts made of stainless steel, aluminum alloy and titanium alloy often lock or jam. These types of metal alloys have good ductility and are fundamentally different from materials such as carbon steel. The specific differences are as follows: Dacromet bolts have anti-corrosion properties, and when the surface is damaged, a thin oxide layer will be produced on the metal surface to prevent further and deeper corrosion. When the Dacromet bolt is locked, the pressure and heat generated between the teeth will destroy and erase the chromium oxide layer between them, causing the metal teeth to directly block or shear, and then adhesion occurs. When the adhesion phenomenon continues, the Dacromet bolt will be completely locked and can no longer be removed or locked. Usually, this series of blocking, cutting, pasting and locking actions will happen in a short time. Therefore, understanding the characteristics of the product and following the correct operation method is the first step to prevent Dacromet bolts from locking.

2. Reasons for the jam:

(1) When assembling and matching bolts and nuts produced by the same heat number, the possibility of Dacromet bolt locking will increase.

(2) The influence of thread accuracy. The matching of external thread grade 6H and internal thread 6H will increase friction.

(3) In the material composition, the higher the copper content, the higher the possibility of thread locking. However, due to the deformation of cold forging, materials with higher copper content may be used when manufacturing Dacromet bolts. The materials used may cause the Dacromet bolts to be locked.

The above are the problems that may occur during the use of Dacromet bolts and the reasons for these problems. I hope it can be helpful to everyone.

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What are the methods to clean Dacromet bolts?

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Heat treatment technology is an important part of advanced manufacturing technology and also plays a very important role in the development of Dacromet bolts and high-end mechanical equipment. As we all know, there is no “chemical composition” will not be called a material, similarly, without “heat treatment” can not be called a material. Through heat treatment technology, the performance of Dacromet bolts can be greatly improved. But there is a problem that cannot be changed by heat treatment, and that is the rust of Dacromet bolts.

Sometimes it is found that the dacromet bolts fixed on the machine are rusty or dirty. In order not to affect the use of the machine, how to clean it has become a very important issue. This makes the performance of Dacromet bolts inseparable from the cleaning agent. Only regular cleaning and maintenance of Dacromet bolts can better play its role. Therefore, here are some commonly used cleaning agents to help you clean up daily.

1. Soluble emulsifying cleaner. This cleaning agent usually consists of emulsifiers, soil, solvents, builders, corrosion inhibitors and a small amount of water. The role of water in the upright cotton is to dissolve the emulsifier. This cleaning agent treatment can dissolve the dirt on the surface of the Dacromet bolts, and it will cause other substances to react during the cleaning process, leaving a layer of anti-rust film on the surface. Emulsifiers and detergents can hold the grease particles on the surface of Dacromet bolts and dissolve them in detergents containing solvents and oils.

2. Alkaline cleaner. Alkaline cleaners are actually a mixture of builders and alkaline earth metal salts of surfactants. It is a widely used cleaner. When maintaining Dacromet bolts, the pH of the cleaning agent is about 7.

The main purpose of using the above two cleaning agents is to ensure the cleaning effect, and secondly because these two cleaning agents are cheap and cost-effective.

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Dacromet bolts play a very important role in the development of the machinery industry

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Looking at the development trajectory of the world, we can intuitively see that the current industry is different from the past industry development. It is closely related to our production and life. Our life is inseparable from the development of the machinery industry. The development of the machinery industry is inseparable from the development of Dacromet bolts. No matter how small our Dacromet bolts are, they are unobtrusive. Once the machinery industry cannot continue to use them, serious consequences will occur. It cannot be said that the entire machinery industry is completely paralyzed, at least, most of its industries will suffer a huge blow. Nothing will go smoothly, it may affect the progress of the project. If the situation is serious, the entire project may not be able to continue without Dacromet bolts.

What incredible things will happen if Dacromet bolts are lost in mechanical engineering. In the investigation of the entire machinery industry, almost all relevant personnel believed that Dacromet bolts are a small part, but they shoulder considerable responsibility. It is very important in engineering operations, it is necessary to link, you can use it wherever you need it. It can be said that if there is no Dacromet bolt, the link cannot be carried out, which will slow down the progress of the entire project.

Once the Dacromet bolt is ignored, it will cause a lot of trouble. If you use it, but don’t see its location correctly, some accidents may happen. For example, if the connection is not tightened, when the object is lifted, if the object is heavy, it may break, resulting in a construction accident. If this happens, you need to treat and check the Dacromet bolt carefully during use, so that this kind of situation can be avoided.

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Some tips on buying gasket products

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At present, gaskets will also be widely used in many industries. Regardless of their small size, they can play a very important role. So how do we choose when we need a gasket?
1. The type and scope of gaskets should conform to the design documents and current effective standards of the country and related industries. Changes in gasket materials and usage standards must be approved.

2. There are many factors that affect the selection of gaskets. Generally, on the premise of ensuring safe operation, you can try to choose a gasket that is cheap, easy to manufacture, easy to install and replace.

3. The thickness of the gasket depends on the specific situation. Generally speaking, if the sealing surface is well treated and the pressure is not too high, a thin gasket should be used. However, when the internal pressure is high, the washer is too thin, which is not conducive to the extension of the bolt, and the rebound of the washer is too small to achieve the required amount of recovery, which may cause leakage. Therefore, when the pressure is higher, a thicker gasket should be selected.
4. In order to ensure the interchangeability of gaskets, the specifications and materials should be unified as much as possible when selecting models. When considering meeting the requirements for use, specifications and materials should be combined as much as possible, and unnecessary problems should be avoided.

5. It is not allowed to use edgeless high-strength gaskets under the conditions of medium gas and high pressure, and corrugated gaskets are also not allowed to be used on serpentine and grooved flanges.

6. Special requirements should be paid attention to. If a certain medium does not allow mixing of fine fibers, fiber gaskets should not be used. If some parts will vibrate violently, you need to choose a gasket with strong vibration resistance, resilience and durability.

7. The gaskets connected to the valve and flange at the bottom of the liquefied balloon tank should be spiral wound gaskets with metal protective rings.

8. When using gaskets, they should be used in a fully annealed state, and softer materials should be used as much as possible. The hardness of the gasket should be lower than the flange sealing surface.

9. The replacement principle of gaskets on imported equipment is to replace the types and materials as they are. When the gasket form or material needs to be replaced due to special reasons, approval is required.

Decho is a professional supplier on gasket products, if you need any , pls contact us by email [email protected]

What should I pay attention to when using gaskets with flange connections?

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What should I pay attention to when using gaskets with flange connections?

Definition of gasket:

The gasket is made of paper, rubber sheet or copper sheet. It is a material placed between two planes to strengthen the seal. It is a sealing element arranged between static sealing surfaces to prevent fluid leakage. When the flange sealing surface is matched with the gasket, the following points should be noted:

1. Thread of flange

Thread is the main direction of flange surface roughness, such as: multi-direction, recording spiral, serration and other surface finish patterns should be as close as possible to the center line of the gasket to be consistent, such as round flanges. The surface texture should be processed into concentric circles or recording spirals to avoid straight lines passing through the flange surface. If there is a straight line across the sealing surface, it will become a direct leakage path. If the gasket needs to be used in conjunction with the flange, then you need to pay attention to this point.

2. Waviness of flange

The waviness is the deviation from the overall flatness. Under normal circumstances, there is no need to consider the waviness problem, but there are two situations that require special attention, because excessive waviness is also a difficult problem to solve.

3. Roughness of flange

Roughness refers to the average value of unevenness calculated from the center of the flange surface, in units of tenths of inches (or meters). For serrated flange surfaces, the typical roughness is 125-500 microinches, while for non-serrated flange surfaces, the roughness is 125-250 microinches. For flanges that are too rough, it is usually impossible to seal the gasket, so you can only choose the softest possible gasket; on the other hand, it is difficult to seal the surface of the flange with a high degree of polishing. This kind of flange should also be avoided because of the sealing The surface needs to have enough “bite marks” to provide enough friction to prevent the gasket from being blown out or extruded or excessive creep.

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What are the advantages of spiral wound gaskets?

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The six advantages of metal spiral wound gaskets are specifically introduced as follows:

1. The metal spiral wound gasket has good compressibility and elasticity.
2. The metal spiral wound gasket has proper plasticity. After compression, it can adapt to uneven sealing surfaces, fill gaps in the sealing surfaces, and ensure good sealing performance when the system temperature and pressure alternate.
3. Metal spiral wound gaskets have good mechanical properties, tensile strength and elongation. The structural density of metal spiral wound gaskets can be determined according to different locking force requirements. The inner and outer steel rings are used to control compression. The surface accuracy of the flange sealing surface contacted by the spiral wound gasket is not high. It is also suitable for occasions where the load is uneven, the joint force is easy to relax, the temperature and pressure will change regularly, and where there is impact or vibration.
4. It has good corrosion resistance, will not be damaged in some extreme media, and will not produce large expansion and contraction.
5. Spiral wound gaskets will not soften at high temperatures, but will shrink at low temperatures.
6. With sufficient strength, the metal wound gasket will not be crushed under the action of external force, nor will it explode under high pressure.

Decho is a professional supplier on spiral wound gaskets . If you need this product, pls contact us by email [email protected]

What is a nut?

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A nut is a nut, a part that is screwed together to fix it with a bolt or screw. According to different materials, the components used in the manufacturing machinery of nuts are divided into several main types such as carbon steel, stainless steel, and non-ferrous metals (such as copper).

The locknut consists of two parts, each part has a staggered cam. Since the inclination angle of the inner wedge design is greater than the angle of the bolt and nut, this combination is tightly bitten into a whole. When vibration occurs, it can prevent the protruding parts of the loose nut from staggering and generating lifting tension, thereby achieving the combined anti-loosening effect.

Embedded nuts are brass nuts made of various embossed wires. The embedded knurled brass nuts we usually contact are all processed by precision automatic lathes.

The main method of operation for embedded knurled copper nuts is injection molding. After heating, it is embedded in plastic parts or directly injection molded. If injection molding is used, the melting point of the nut needs to be higher than 200°C, so that the embedded nut is melted by heat. After inserting the plastic part, the temperature rises rapidly.

After injection molding, the plastic body rapidly cools and crystallizes. If the temperature of the embedded nut is still high, you can pour it into the place where the copper nut contacts the plastic part and starts to loosen or crack. Therefore, copper nuts can be used instead of carbon steel nuts in the injection molding of embedded nuts.

There are two methods to form the external die knurling of the embedded copper nut. One is to use copper raw materials to draw patterns and then produce them on upper equipment. Usually, the figure drawn in this way is straight, the other is to use a round copper material. In the production process, the round copper material is directly embossed. This processing method can produce some non-standard size knurled copper nuts. The embossing shape of the embedded copper nut can be selected by the user, such as mesh or various scroll patterns.

Tianjin Decho is a professional supplier on nuts products . If you need any for your project , pls contact us by email [email protected]

How to judge the strength of hexagon socket bolts?

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Cylinder head hexagon socket screws, also known as hexagon socket bolts, cup head screws and hexagon socket screws, have different names, but they have the same meaning. Commonly used hexagon socket screws also have 4.8, 8.8, 10.9 and 12.9. Also called hexagon socket bolt, the head is hexagonal and cylindrical. According to the material, there are stainless steel and iron.

Iron is classified according to the strength grade of hexagon socket bolts. There are 4.8 grade hexagon socket screws, 8.8 grade hexagon socket screws, 10.9 grade hexagon socket screws and 12.9 grade hexagon socket screws. Hexagon socket bolts of grade 8.8-12.9 are called high-strength hexagon socket bolts.

In the process of steel structure construction, high-strength hexagon socket bolts are often used. What is a high-strength hexagon socket bolt? It should have high-strength friction and pretension. However, for convenience, people often omit “friction” and “pretension”. There are two misunderstandings:

Misunderstanding 1: Bolts with a material grade exceeding 8.8 are equivalent to “high strength”

Compared with ordinary bolts, the core of high-strength hexagon socket bolts is not the strength of the material itself, but the form of stress. The so-called stress form is the shear resistance when preload and static friction are applied.

The high strength mentioned in the bolt standards of the United States and the United Kingdom is only 8.8 and 10.9, while ordinary bolts have not only 4.6, 5.6, but also 8.8, 10.9, etc., so you cannot rely on materials to determine whether it is a high-strength hexagon socket bolt.

Misunderstanding 2: The bearing capacity of high-strength hexagon socket bolts is higher than that of ordinary bolts

The strength of high-strength hexagon socket bolts is not determined by its carrying capacity, but by high rigidity, high safety performance and strong destructive resistance.

High-strength hexagon socket bolts mainly have the characteristics of small elasto-plastic deformation in terms of high strength and high joint stiffness. Therefore, under a certain combined load, the use of high-strength bolts cannot reduce the number of bolts, but the deformation is small and the stiffness is large, so it is very suitable for occasions that require high stiffness.

Decho is a professional supplier on hexagon socket bolts products , if you need any , pls feel free to contact us by email [email protected]

What is the working principle of the nut?

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A nut is a nut, a part that is screwed together to fix it with a bolt or screw. The materials are divided into carbon steel, stainless steel, non-ferrous metals (such as copper), etc.

Nuts are parts that tightly connect mechanical equipment. Through the internal thread, nuts and bolts of the same specification can be connected together. The working principle of the nut is to self-lock through the friction between the nut and the bolt. However, the reliability of this self-locking will be reduced under dynamic load. In some important occasions, we will take some anti-loosening measures to ensure the reliability of the nut lock. One of the anti-loose measures is to use anti-loose nuts.

There are also three types of lock nuts:

1) Use two same nuts to tighten the same bolt, and increase the tightening torque between the two nuts to make the bolt connection reliable.
2) Special lock nuts need to be used together with lock washers. The special lock nut is not a hexagonal nut, but a round nut in the middle.
3) Drill threaded holes from the outer surface of the nut to the inner thread surface for screwing in small-diameter countersunk screws. The purpose is to tighten the centripetal force to prevent the lock nut from loosening.

There is a small piece of copper inlaid on the lock nuts with better quality currently on the market. The copper piece matches the thread of the lock nut on the inner surface of the nut to prevent the radial jack screw from directly contacting the locking thread and damaging fasten the screw nut. This kind of locknut has gradually begun to be applied to the shaft end locking of rotating parts, such as anti-loosening of the bearing at the mounting end of a ball screw.

TJ DECHO is a professional supplier on nut products , if you need any , pls feel free to contact us by email [email protected]

What are the anti-corrosion treatment methods for hexagon head bolts?

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When using hexagon head bolts, anti-corrosion treatment is a very important requirement. Depending on the corrosion conditions, different treatment methods can be used.

1) Oxidation

Since it hardly has the ability to prevent rust due to blackening, it will quickly rust without oil. The torque preload consistency of the blackened square column template is also poor. If improvement is needed, grease can be applied to the internal thread during assembly and then tightened.

2) Sherardizing

Sherardizing is a solid metallurgical thermal diffusion coating of zinc powder. Its uniformity is good, and a uniform layer can be obtained in the threads and blind holes of hexagon head bolts. Its processing process is pollution-free and environmentally friendly.

3) Electro-galvanized

Hydrogen embrittlement is prone to occur in the electrogalvanizing process, and the consistency is poor. Connect and assemble with a square column template with a height of 500. When butting and assembling hexagon head bolts, please pay attention to the consistency of the socket interface. You can take an auxiliary bracket, open the auxiliary bracket, and clamp the auxiliary bracket to the wooden side of the junction of the two square column templates according to the marked position, and tighten it on the other side of the same height to mark the position. First place a single piece of toggle clamp horizontally on the auxiliary support. Place the elbow up so that the end of the second clip passes through the curved space of the clip head, and then place it horizontally on the auxiliary support. In order to improve the torque-pre-tightening force consistency, the method of coating lubricating substances after plating can also be used to improve and increase the torque of the hexagon head bolts.

4) Cadmium plating

The corrosion resistance of cadmium coating is very good, especially in the ocean atmosphere, its corrosion resistance is better than other surface treatments. The waste liquid treatment in the cadmium electroplating process is expensive, and the price is about 15-20 times that of electro-galvanized zinc. Therefore, it is not suitable for hexagonal head bolts in general industries, but suitable for fasteners for oil drilling platforms and HNA aircraft.

5) Chrome plating

The chromium coating is very stable in the atmosphere, is not easy to change color and lose luster, has high hardness and good wear resistance. Chrome plating on hexagon head bolts is usually used for decoration.

Decho is a professional supplier on all kinds of bolts and nuts products . If you need any for your project , pls contact us by email [email protected]