A Hex Flange Head Self Drilling Screw with a Plastic Washer is a specialized multi-component fastener engineered for efficient and secure attachment, particularly in applications where sealing, vibration dampening, or protection of the joined material is crucial. It combines the drilling and fastening capabilities of a self-drilling screw with the added benefits of an integrated washer system.

Key Components and Features:

1. Self-Drilling Screw:
   • Self-Drilling Point: Features a sharpened, drill bit-like point that can create its own pilot hole, tap its own threads, and fasten materials (typically metal to metal, or metal to wood) in a single operation, eliminating the need for pre-drilling.
   • Hex Flange Head:
     • Hexagonal Drive: Allows for installation with a wrench, socket, or hex bit drive, providing excellent torque transmission and reducing cam-out, especially when high fastening force is required.
     • Integrated Flange: A wide, unthreaded flange is incorporated directly beneath the hexagonal head. This flange acts as a built-in washer, distributing the clamping force over a larger surface area, which helps to:
       • Prevent pull-through of thin materials.
       • Provide a larger bearing surface for increased stability.
       • Reduce localized stress on the fastened material.
2. Plastic Washer:
   • This component is typically pre-assembled under the flange of the screw. Common materials include EPDM rubber, PVC, or nylon. The plastic washer serves several critical functions:
     • Sealing: Creates a watertight or airtight seal between the screw head and the fastened material, preventing moisture ingress (e.g., in roofing or cladding).
     • Vibration Dampening: Helps to absorb vibrations, reducing loosening over time and preventing noise.
     • Material Protection: Protects the surface of the fastened material from damage (scratches, crushing) that could occur from direct contact with the metal flange, especially important for coated or delicate finishes.
     • Thermal Expansion/Contraction Accommodation: In some applications (like roofing), the washer allows for slight movement of the material due to thermal changes without compromising the seal.
     • Electrical Insulation: Can provide a degree of electrical isolation between the screw and the fastened material in certain applications.

Typical Applications:

• Roofing and Cladding: Widely used for fastening metal roofing sheets, wall panels, and siding to purlins or girts, where a weatherproof seal is essential.
• HVAC Systems: Securing ductwork, external units, and other components, often benefiting from the sealing and vibration dampening properties.
• Trailer and Vehicle Manufacturing: Attaching exterior panels, trim, and components where protection against moisture and vibration is needed.
• Light Gauge Metal Construction: Fastening various metal sheets and profiles in building applications.
• Agriculture: Securing corrugated metal in barns, sheds, and agricultural buildings.
• Signage Installation: Attaching signs to various substrates while protecting the sign face.

Advantages:

• Efficiency: Self-drilling capability saves time and labor by eliminating pre-drilling.
• Superior Sealing: The integrated plastic washer provides an effective seal against water and air intrusion.
• Enhanced Durability: Protects the fastened material from damage and reduces loosening from vibration.
• Improved Clamping Force Distribution: Flange head spreads the load, preventing pull-through.
• Reliable Drive: Hex head offers strong torque transfer and reduces cam-out.
• Versatility: Suitable for a wide range of outdoor and industrial applications requiring a secure, sealed, and protected fastening.