M8-1.00 x 50 MM  DIN 960 8.8 Hex Head Screw

Metric Grade 8.8 Zinc Cr3 Plating Hex Head Cap Screws: Specifications and Industrial Applications

Metric Grade 8.8 zinc Cr3 plated hex head cap screws are widely used fasteners that combine high strength with enhanced corrosion resistance. These screws are commonly employed in industries where both mechanical performance and protection against environmental factors, such as corrosion, are critical. The “8.8” grade refers to the mechanical properties of the screw, while the zinc Cr3 (chromium trivalent) plating offers superior durability in outdoor or industrial environments.

Specifications

• Material: Metric Grade 8.8 hex head cap screws are typically made from medium carbon steel, with a carbon content ranging from 0.25% to 0.55%. This material is heat-treated to achieve a tensile strength of 800 MPa and a yield strength of 640 MPa. The heat treatment process ensures the screws maintain their strength under mechanical stress, making them ideal for demanding applications.

• Zinc Cr3 Plating: The screws are coated with a trivalent chromium (Cr3) zinc plating. This type of coating offers significant advantages over traditional hexavalent chromium (Cr6) coatings, as Cr3 is more environmentally friendly and provides superior corrosion resistance. Zinc plating is essential for protecting fasteners against oxidation and rust, especially when exposed to moisture and harsh weather conditions. Cr3 plating enhances the plating's adhesion, durability, and resistance to corrosion, without the environmental and health concerns associated with Cr6.

• Thread Type: These fasteners feature metric threads (M-series) according to the ISO 261/ISO 262 standards. The thread sizes typically range from M6 to M30, though they can be customized for specific applications, ensuring compatibility with various mechanical systems.

• Strength: Grade 8.8 hex head cap screws possess a tensile strength of 800 MPa and a yield strength of 640 MPa, which allows them to withstand high levels of stress, vibration, and dynamic loads. These mechanical properties make them ideal for securing critical parts in heavy-duty applications.

Industrial Applications

Metric Grade 8.8 zinc Cr3 plated hex head cap screws are used extensively across multiple industries where durability and high strength are essential. The corrosion resistance provided by the Cr3 zinc plating makes these screws particularly suitable for outdoor or high-moisture environments.

• Automotive Industry: These fasteners are commonly used in automotive manufacturing, including the assembly of engines, exhaust systems, and chassis. The corrosion resistance ensures that the screws can perform reliably over time, even when exposed to road salts, water, and other environmental factors.

• Construction and Infrastructure: In construction, these screws are used for securing structural steel components, bridge assemblies, and facades. Their resistance to corrosion makes them ideal for outdoor applications, particularly in coastal or industrial environments where exposure to elements like rain and salt is common.

• Agriculture and Heavy Equipment: Equipment used in agriculture and heavy machinery often operates in harsh conditions, such as exposure to moisture, dirt, and chemicals. Zinc Cr3 plated Grade 8.8 screws are employed to assemble various components of farm machinery, construction equipment, and heavy-duty vehicles, where high strength and protection against rust are essential.

Conclusion

Metric Grade 8.8 zinc Cr3 plated hex head cap screws provide an ideal balance of strength, durability, and corrosion resistance. Their use in industries such as automotive, construction, and agriculture ensures that critical components remain securely fastened, even under the most demanding environmental conditions. With the added benefit of environmentally friendly Cr3 plating, these fasteners offer a sustainable, reliable solution for high-performance applications.