Release time：2020-01-16 18:44 Browse：
Extending the service life of construction screws mainly depends on choosing the right surface treatment, installing them correctly, and providing proper isolation and protection. Based on the screw's environment, you can focus on the following aspects.
Upgrade Surface Treatment According to the Environment
The corrosion resistance of a screw directly determines its service life. Standard electroplated zinc may show rust within 48 to 96 hours in outdoor or humid environments, so a more durable coating should be selected according to the corrosion level.
For ordinary outdoor or industrial areas, choose Dacromet, also known as zinc-aluminum coating. Its neutral salt spray resistance can reach 500 to 1,000 hours, and it has no hydrogen embrittlement risk. Alternatively, choose a chromium-free coating system with a salt spray rating starting at 1,000 hours.
For coastal, chemical, and other highly corrosive environments, heavy-duty anti-corrosion coatings are required, with salt spray requirements of over 1,000 hours, and sometimes up to 1,500 to 2,500 hours.
When drilling hardness is required, consider bimetallic composite self-drilling screws. The shank and head are made of 304 or 316 stainless steel for corrosion resistance, while the drill tip uses high-carbon alloy steel to ensure drilling hardness, balancing corrosion resistance and penetration.
Install Properly and Protect the Coating
The installation process is the most likely to damage the screw's anti-corrosion layer, causing the cut and thread areas to rust first.
Tighten vertically and avoid over-tightening. Keep the screw perpendicular to the panel surface and ensure the washer is compressed. Use a torque-controlled electric screwdriver to avoid coating damage from over-tightening. Once the coating on the screw head is damaged, the exposed base metal becomes the starting point for corrosion.
Choose the correct drill tail type. Select the appropriate drill tail according to the panel thickness, and avoid forced tightening, which can cause extensive wear to the thread coating.
Use micro-pocket oil storage technology if available. Some patented technologies create micro-pockets on the screw surface and fill them with anti-rust coating. During installation, the coating is squeezed into the cut gap, creating a seal. Even if the surface layer is scraped off, the cut area remains protected.
Provide Isolation and Daily Protection
Isolate dissimilar metals. Carbon steel screws must never directly contact aluminum panels or ACQ-treated wood, otherwise galvanic corrosion will occur and the screws will rust faster. Insulating washers must be installed to break the corrosion circuit.
Apply additional protection after installation. For highly corrosive environments, apply anti-rust oil or protective sealant around the screw head and surrounding area after tightening, as a final barrier. For indoor applications such as gypsum board ceilings, the screw heads should also be coated with anti-rust paint to prevent rust bleeding and maintain appearance.
Perform regular maintenance. For screws exposed to harsh environments over the long term, regularly clean surface dirt and reapply protective grease to effectively extend their service life.
In summary, choosing the right coating is the foundation, proper installation is the key, and isolating dissimilar metals and performing regular maintenance are the safeguards. If you can tell me the specific application scenario, such as coastal color steel tiles, photovoltaic brackets, or indoor ceilings, I can help you determine the most suitable corrosion protection level
