Seven treatment methods for preventing corrosion of anti-theft screws?

For anti-theft screws, anti-corrosion treatment is a very important step, and with the development of technology, there are now more and more anti-corrosion treatment methods. According to different corrosion conditions, we should adopt different treatment methods. Today, the technical personnel of Nissan Fasteners will briefly describe seven common anti-corrosion treatment methods.
1、 Oxidation
Because the surface of the screw has almost no rust prevention ability after blackening, the screw will quickly rust when the surface is free of oil. After blackening, the torque pre-tightening force of the screw is also about to decrease. If you want to improve this situation, you can apply some grease to the threads inside the screws during assembly, and then tighten them.
Seven treatment methods for preventing corrosion of anti-theft screws
2、 Zinc infiltration
Zinc infiltration is a solid-state metallurgical thermal diffusion coating of zinc powder. The uniformity of this coating is relatively good, and it can be evenly applied even in the threaded parts and blind holes of the screws. Moreover, this processing process is pollution-free and environmentally friendly.
3、 Electrogalvanizing
Hydrogen embrittlement is more likely to occur during the electroplating process, and the consistency of the screws after electroplating treatment will decrease. In order to improve the consistency of torque and pre-tightening force, lubricating substances can be coated on the surface of the screw after electroplating, which can increase the torque force of the screw.
4、 Electroplating cadmium
The corrosion resistance of cadmium plating is outstanding, especially for bolts used in marine atmospheric environments. After cadmium plating treatment, the corrosion resistance effect is relatively good. During the processing of electroplating cadmium, there will be waste liquid generated, and treating the waste liquid requires a considerable fee. Therefore, the cost of electroplating cadmium treatment is relatively high. Compared with electroplating zinc, its processing cost is 15-20 times higher. Therefore, only screws used in petroleum drilling platforms and aerospace industries will use this treatment method.
5、 Chromium plating
Chromium plating can maintain a stable state in the atmosphere, which is not easy to change color or lose luster. It has high hardness and good wear resistance. Generally speaking, the use of chromium plating on screws is mainly for decorative purposes.
6、 Phosphating
There are two ways to phosphatize screws, one is zinc-based phosphating and the other is manganese-based phosphating, each with its own advantages and disadvantages. The lubrication performance of zinc-based phosphating is much better than that of manganese-based phosphating, but manganese-based phosphating has better corrosion resistance and wear resistance than zinc plating.
7、 Silver and nickel plating
Silver plating can not only provide corrosion protection but also provide lubrication. Due to cost reasons, generally speaking, there are more silver plated small screws. Nickel plating can not only improve anti-corrosion performance but also enhance conductivity.
The seven treatment methods for preventing corrosion of anti-theft screws are introduced here, and users can choose the appropriate treatment method based on actual usage requirements and conditions.