Coil Nails Rust Prevention Process

Coil Nail Introduction

The coil nail is a type of fastener that is currently widely used around the world. It is created by using a nailing machine to weld ordinary bulk iron nails and copper-plated iron wire in an orderly manner.

Coil nails come in two main categories: flat-top coil nails and cone-top coil nails. Generally, flat-top coil nails contain 200-300 nails, while cone-top coil nails contain 400 nails.

These coil nails are extensively used in industries such as wood furniture, board packaging, and building decoration, where a large number of nails are required. They are especially useful for binding batch wood products and in situations where manual hammering is difficult.

Using a pneumatic gun, it is possible to complete 100 nails per minute, offering advantages such as time and labor savings, strong penetration force, and powerful fastening capabilities. This can significantly reduce labor intensity, improve working conditions, enhance production efficiency, and ensure work quality.

Coil Nails

Coil Nails Produce Process

Wire-Drawing — Nail-Making — Threading — Collating

Why should coil nails undergo surface treatment?

From the above process, it can be seen that after the production of loose nails, they must be polished to ensure the smoothness of the nail surface and to form a protective film on the surface, preventing rust during transportation, storage, and sale.

However, in the process of making coil nails, the above protective film will be damaged to a certain extent due to friction and high-temperature welding on the coiling machine, reducing its rust resistance.

In the sales process of coil nails, they go through various stages from producers to users, including domestic storage, land transportation, loading onto ships, overseas wholesalers, retailers, and more.

During this process, environmental factors such as air humidity, temperature, and salt content have a significant impact, making coil nails more prone to rust.

Rust not only affects the appearance of the nails but also contaminates pneumatic nail guns, accelerating wear and reducing sensitivity, thus shortening the lifespan of the pneumatic gun. Therefore, it is essential to carry out surface treatment on coil nails before packaging.


Principle of Rust Prevention

From the perspective of rusting mechanism, rusting is a chemical or electrochemical reaction.

In a humid environment, this type of chemical or electrochemical reaction of metals occurs easily.

The greater the concentration of oxygen, moisture, and dust in the air, the faster this reaction occurs.

Conversely, in a dry environment or one isolated from oxygen and dust, the speed of this reaction is extremely slow, or it may not occur at all.

Therefore, the rust prevention measure for metals is to keep the metal dry or to isolate it from contact with oxygen and dust in the air.

Therefore, if a protective film can be reformed on the surface of coil nails, isolating them from contact with air, the purpose of rust prevention can be achieved.


Methods of Rust Prevention

The ideal method is to immerse coil nails in a surface treatment solution to form a protective film. The anti-rust paint method is a measure taken to prevent coil nails from rusting by isolating them from the metal’s characteristics.

Anti-rust paint is a liquid with high viscosity and strong adhesion. When coil nails are sprayed with anti-rust paint, a dense and corrosion-resistant paint film is formed on the surface.

This film prevents reactions with oxygen in the air in both dry and humid environments, protecting the coil nails from corrosion caused by oxygen, moisture, and various harmful substances, thus allowing the coil nails to be stored for long periods without rusting.

There are various types of anti-rust paint with different uses. Coil nails have the following requirements for anti-rust paint:

  • Bright Color: After being treated with anti-rust paint, coil nails are required not only to resist rust for a long time but also to have a bright appearance, giving a pleasing first impression.Currently, most coil nails produced by manufacturers both domestically and internationally are primarily golden yellow.To meet the requirements of customers at home and abroad and align with the international coil nail market, it is required that the anti-rust paint for coil nails be golden yellow.


  • High Transparency: Most anti-rust paints on the market are not transparent. When coil nails are treated with non-transparent anti-rust paint, a non-transparent paint film adheres to the surface, causing the coil nails to lose their metallic luster, which is not aesthetically pleasing. Additionally, the non-transparent paint film is relatively thick, and its adhesion strength does not meet the requirements. Therefore, considering the aesthetics and the firmness of the paint film on the coil nails, it is required that the anti-rust paint for coil nails have high transparency.


  • Rapid Drying: When treating coil nails with anti-rust paint, it is required that the nails dry quickly after treatment, allowing for rapid packaging and increasing the turnover speed of the paint immersion area. The drying time for anti-rust paint should not exceed 10 minutes, with 5 minutes being the ideal time.


  • Strong Adhesion: From the factory to end use, coil nails may experience paint film peeling or damage during transportation due to vibration and other reasons. Therefore, the anti-rust paint needs to have strong adhesion and be resistant to cracking. When the coil nails are driven into the material, the paint film, along with the nail, undergoes frictional heating and melting, bonding the nail to the material, thereby increasing the fastening force. Therefore, the anti-rust paint should have strong adhesion, and firmness, and be resistant to peeling.


Method of Using Anti-Rust Paint

Process for Coil Nail Rust Prevention:

Paint Mixing – Immersion – Baking – Inspection, Packaging

Method of Using Anti-Rust Paint for Coil Nails: The anti-rust paint is mixed with a special solvent in the appropriate ratio to obtain the paint solution.

When mixing the paint solution, the anti-rust paint and the special solvent should be thoroughly stirred to ensure complete mixing.

Then, the coil nails are immersed in this paint solution for about 20 seconds. To ensure uniform color inside and outside the coil nails after immersion, the coil nails should be moved up and down in the paint solution 3-4 times.

After removal, any excess paint solution on the surface of the coil nails should be gently blown away with compressed air to ensure uniform coverage. Subsequently, the coil nails are left to air dry or are dried with added heat.

During the use of anti-rust paint, special attention should be paid to three points:

  • Strictly control the paint mixing ratio. If the paint solution is too thick, the drying time for the coil nails after immersion will be longer, and the color of the paint film and coil nails will be uneven.If the paint solution is too thin, the color of the coil nails after immersion will be too light, resulting in a thin paint film that is not effective for rust prevention and is aesthetically unpleasing.
  • Ensure that the paint film is uniform after immersion.
  • If a drying device is used to dry the coil nails after immersion, the drying temperature should be strictly controlled. The drying temperature is generally 60–70°C, with a maximum temperature not exceeding 80°C. Otherwise, the paint film may burn and peel off, losing its protective effect on the coil nails. More importantly, excessively high temperatures may cause a fire.


Problems and Countermeasures in the Use of Anti-Rust Paint for Coil Nails

In the initial use of anti-rust paint for coil nails, issues such as the nails turning green, extended drying times, white tips, and clumping may arise, leading to quality accidents and even the production of defective products.

Through multiple observations, we have found that the weather directly affects the effectiveness of the paint immersion process.

Better weather leads to better paint immersion results, while poor weather results in subpar immersion.

Through observation and research, we have discovered a close relationship between the effectiveness of the paint immersion process and the relative humidity of the air.

We have concluded that the higher the relative humidity, the worse the paint immersion results, and conversely, the lower the relative humidity, the better the paint immersion results.

To address issues arising from paint immersion during high relative humidity, we have added a small amount of ethylene glycol ether as a moisture-proofing agent when preparing the anti-rust paint.

This solution resolves the problems of prolonged drying, white tips, and clumping that occur during rainy days.


In conclusion, the use of anti-rust paint for coil nails has effectively addressed the issue of rusting during storage and transportation.

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