What is the purpose of spraying Xylan coating on bolts

Source：www.sdhlwj.com Release date： 2025年12月22日

Information summary：The core function of bolt spraying Xylan coating (a fluoropolymer coating containing polytetrafluoroethylene (PTFE)) is to improve corrosion resistance, lubrication, and wear resistance, while enhancing sealing reliability, solving the problems of corrosion, jamming, and adhesion of bolts under harsh working conditions, extending service life, and reducing maintenance costs. The specific functions

The core function of bolt spraying Xylan coating (a fluoropolymer coating containing polytetrafluoroethylene (PTFE)) is to improve corrosion resistance, lubrication, and wear resistance, while enhancing sealing reliability, solving the problems of corrosion, jamming, and adhesion of bolts under harsh working conditions, extending service life, and reducing maintenance costs. The specific functions can be divided into the following five categories:
1. Corrosion and rust prevention
Xylan coating can form a dense protective film on the surface of bolts, isolating the corrosion of oxygen, moisture, acid alkali salt media, and industrial chemicals, especially suitable for strong corrosive environments such as marine, chemical, and outdoor environments.
Excellent resistance to corrosive media such as chloride ions and hydrogen sulfide, which can prevent bolt pitting and intergranular corrosion;
Compared to traditional anti-corrosion processes such as galvanizing and chrome plating, Xylan coating has a longer anti-corrosion life and can withstand more than 1000 hours of salt spray testing without significant corrosion.
2. Self lubricating anti jamming, achieving oil-free assembly
The PTFE component contained in the coating has a low friction coefficient (0.05-0.15), which can endow the bolt with excellent self-lubricating performance:
No additional grease is required during assembly to avoid secondary pollution caused by grease adsorbing dust, suitable for clean industries such as food, medicine, electronics, etc;
Effectively prevent bolts from biting, sticking or even sticking to nuts/substrates under high temperature, high pressure or vibration conditions, greatly reducing the difficulty of disassembly, especially suitable for bolts made of easily sticky materials such as stainless steel and high-temperature alloys.
3. High temperature resistance and medium stability
The high temperature resistance of Xylan coating is outstanding, and different models can withstand a wide temperature range of -200 ℃~+260 ℃. Some models can even work for a short period of time above 300 ℃ without decomposing harmful substances at high temperatures.
At the same time, the coating has good resistance to organic solvents, hydraulic oil, fuel oil and other media, and will not swell or peel off due to contact with the media, making it suitable for bolt protection in harsh scenarios such as engines and hydraulic systems.
4. Wear resistance and resistance to micro motion wear
The combination of the polymer matrix of the coating and fillers (such as glass flakes and metal powders) can enhance the hardness and wear resistance of the bolt surface, reducing thread wear during tightening and loosening of the bolt;
For bolts under vibration conditions, it can effectively resist micro motion wear (wear caused by small relative motion between threads), prevent thread failure, and ensure long-term reliability of the connection.
5. Enhance sealing performance to prevent leakage
The coating has good film-forming properties and can fill small gaps in bolt threads, forming a sealing barrier. When used in conjunction with sealing gaskets, it can further enhance the sealing of bolt connections and prevent fluid (liquid, gas) leakage. It is suitable for high sealing requirements such as pressure vessels and pipeline flanges.
6. Typical application scenarios
Marine engineering: bolts for ships and offshore wind power equipment to resist seawater corrosion and salt spray erosion;
Chemical equipment: reaction kettle, pipeline flange bolts, resistant to acid and alkali medium corrosion;
Automotive/Aerospace: Engine cylinder head, chassis bolts, achieving high-temperature anti sticking and anti-corrosion;
Food and medicine: Equipment fasteners that meet the requirements of oil-free assembly and clean hygiene.

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