DIN7504K Roofing SDS Screw

Product Construction Design & Industrial Fabrication Process

The screw body is made of high-strength carbon steel or stainless steel (410/304/316), processed via thread rolling, heat treatment and anti-corrosion surface finishing. The drill point is precision formed for clean drilling and stable penetration capacity, avoiding slipping or thread damage during installation. The key feature is the integrated composite washer: rigid metal backing washer + EPDM ethylene propylene diene monomer rubber, tightly bonded as one piece. When tightened, the EPDM layer compresses evenly to fill gaps completely, blocking rainwater, dust and air penetration effectively. The six-sided hex flange head supports high torque socket tool installation, providing uniform clamping force and preventing loosening under wind vibration and temperature cycling. All products pass hardness testing, salt spray corrosion testing and pull-out load testing to meet long-term outdoor building application standards.

Product Parameter

Key Performance Merits & Practical Engineering Deployment

1. Superior EPDM composite waterproof sealing. The integrated EPDM rubber washer forms a tight permanent seal against the metal surface after tightening, preventing water leakage, condensation and corrosion at screw penetration points, greatly extending roof system service life, suitable for rainy, coastal and high-humidity environments.

2. High-efficiency self-drilling performance. Precision hardened drill tip directly drills through specified thin steel substrates, eliminating pre-drilling operations, saving construction time and labor cost, with clean thread forming and firm thread engagement.

3. Hex flange high-torque drive design. Six-sided hex head works perfectly with standard socket tools, delivering consistent clamping force, avoiding cam-out slippage, resisting cyclic wind vibration and thermal expansion contraction, maintaining stable fastening force long-term.

4. Enhanced anti-corrosion & weather resistance. Multiple surface treatments plus EPDM weather-resistant material achieve long-term anti-rust and anti-aging performance, passing long-duration salt spray tests, suitable for 15+ years of outdoor service life requirements.

5. Wide industrial matching range. Ideal for metal roofing systems, solar mounting frames, light steel structures, warehouse panels, greenhouses, carport frames and exterior facade cladding, widely adopted in construction, solar energy, agricultural and industrial building projects.

FAQ

Q1: What is the main difference between EPDM composite washer drill screws and ordinary drill screws? 

A1: The EPDM composite bonded washer creates an integrated waterproof seal, solving roof leakage issues at fastener holes, while regular drill screws lack sealing function and are prone to water penetration and rust over time.

Q2: What steel thickness can these self-drilling screws penetrate? 

A2: Different drill point versions support specific thin gauge steel sheet thicknesses, please confirm specifications according to actual substrate thickness to ensure proper drilling and fastening effect.

Q3: Can I customize colors and lengths for large orders? 

A3: Yes, we offer custom color coating, full length specifications, stainless steel grades and logo marking services for bulk orders, supporting OEM & ODM requirements.

Q4: How long can the EPDM washer last outdoors? 

A4: High-quality EPDM rubber has excellent UV and aging resistance, maintaining sealing performance for many years in open-air environments, matching the service life of metal roof panels.

Q5: Do you provide samples for on-site testing? 

A5: Yes, free sample support is available for customers to verify drilling performance, sealing effect and corrosion resistance before formal bulk orders.