What materials are used to make Dacromet Double - head Bolt?

As a supplier of Dacromet double - head bolts, I am often asked about the materials used in their production. Dacromet double - head bolts are essential components in various industries, known for their high corrosion resistance and reliable performance. In this blog, I will delve into the materials that go into making these remarkable bolts.

1. Base Metal Materials

The base metal is the core of the Dacromet double - head bolt, providing the necessary strength and structural integrity.

Carbon Steel

Carbon steel is one of the most commonly used base metals for Dacromet double - head bolts. It is an alloy of iron and carbon, with carbon content typically ranging from 0.05% to 2.1%. Low - carbon steel (carbon content less than 0.3%) is relatively soft and ductile, making it easy to machine. Medium - carbon steel (carbon content between 0.3% and 0.6%) offers a good balance of strength and ductility, suitable for general - purpose applications. High - carbon steel (carbon content greater than 0.6%) has high strength and hardness but is less ductile.

For example, in applications where the bolt needs to withstand moderate loads and stresses, medium - carbon steel is a popular choice. The 10.9 Grade Black Double - head Bolt often uses carbon steel as its base material. The 10.9 grade indicates a high - strength bolt, and carbon steel can be heat - treated to achieve the required mechanical properties.

Alloy Steel

Alloy steel is another important base metal for Dacromet double - head bolts. It is formed by adding various alloying elements such as chromium, nickel, molybdenum, and vanadium to carbon steel. These alloying elements enhance the mechanical properties of the steel, including strength, toughness, and corrosion resistance.

Alloy steel is commonly used in high - performance applications where the bolt needs to withstand extreme conditions, such as high temperatures, high pressures, or corrosive environments. For instance, in the automotive and aerospace industries, alloy steel Dacromet double - head bolts are used to ensure the reliable operation of engines and other critical components.

Stainless Steel

Stainless steel is a popular choice for applications where corrosion resistance is of utmost importance. It contains at least 10.5% chromium, which forms a passive oxide layer on the surface of the steel, protecting it from corrosion. There are different grades of stainless steel, such as 304 and 316.

304 stainless steel is a general - purpose stainless steel with good corrosion resistance in most environments. 316 stainless steel, on the other hand, contains molybdenum, which further enhances its corrosion resistance, especially in chloride - containing environments. The GB901 Double - headed Bolt can be made from stainless steel, providing long - term durability in outdoor or corrosive settings.

2. Dacromet Coating Materials

The Dacromet coating is what gives these double - head bolts their excellent corrosion resistance. Dacromet is a water - based coating system that consists of zinc, aluminum flakes, and a special binder.

Zinc and Aluminum Flakes

Zinc and aluminum are the main active components in the Dacromet coating. Zinc is a sacrificial metal, which means it corrodes preferentially to the base metal. When the Dacromet - coated bolt is exposed to a corrosive environment, the zinc in the coating reacts with oxygen and moisture to form a protective layer of zinc oxide and zinc hydroxide. This layer acts as a barrier, preventing further corrosion of the base metal.

Aluminum also contributes to the corrosion resistance of the coating. Aluminum forms a thin, dense oxide layer on its surface, which is highly resistant to corrosion. The combination of zinc and aluminum flakes in the Dacromet coating provides a synergistic effect, enhancing the overall corrosion protection of the bolt.

Binder

The binder in the Dacromet coating plays a crucial role in holding the zinc and aluminum flakes together and adhering them to the surface of the base metal. It is usually an inorganic or organic polymer. Inorganic binders, such as silicates, offer good heat resistance and chemical stability. Organic binders, on the other hand, can provide better flexibility and adhesion.

The Dacromet coating process involves applying the coating to the surface of the double - head bolt through a dipping or spraying method. After application, the bolt is cured at a specific temperature to form a hard, durable coating.

3. Other Materials and Considerations

In addition to the base metal and Dacromet coating materials, there are other factors and materials to consider in the production of Dacromet double - head bolts.

Surface Treatment Additives

Sometimes, surface treatment additives are used to improve the performance of the Dacromet coating. For example, some additives can enhance the lubricity of the coating, making it easier to install the bolt. Others can improve the adhesion of the coating to the base metal or increase its resistance to abrasion.

Thread Locking Compounds

In some applications, thread locking compounds may be used in conjunction with Dacromet double - head bolts. These compounds can prevent the bolt from loosening due to vibration or other dynamic forces. There are different types of thread locking compounds, such as anaerobic and silicone - based compounds.

4. Quality Control and Standards

As a supplier, we adhere to strict quality control measures to ensure the quality of our Dacromet double - head bolts. We follow international standards such as ISO, ASTM, and GB. These standards specify the requirements for the chemical composition, mechanical properties, and dimensional accuracy of the bolts.

For example, the M10 Double Head Bolt must meet the relevant standards for its diameter, pitch, and length. We also conduct various tests, such as tensile tests, hardness tests, and salt spray tests, to ensure that the bolts meet the required performance criteria.

Conclusion

In conclusion, the materials used to make Dacromet double - head bolts are carefully selected to provide the best combination of strength, corrosion resistance, and performance. The base metal, whether it is carbon steel, alloy steel, or stainless steel, provides the structural integrity of the bolt. The Dacromet coating, with its zinc and aluminum flakes and binder, offers excellent corrosion protection.

If you are in need of high - quality Dacromet double - head bolts for your projects, we are here to assist you. Our extensive range of products, including the 10.9 Grade Black Double - head Bolt, GB901 Double - headed Bolt, and M10 Double Head Bolt, can meet your diverse requirements. Contact us today to discuss your specific needs and start a procurement negotiation.

References

• ASM Handbook Committee. ASM Handbook Volume 1: Properties and Selection: Irons, Steels, and High - Performance Alloys. ASM International, 2007.
• ASTM International. ASTM Standards for Fasteners. ASTM International, various years.
• ISO Technical Committee. ISO Standards for Fasteners. International Organization for Standardization, various years.