Zinc Plated Hex Washer Head Self Drilling Screw with EPDM Washer C1022A (DIN 7504K)

The Hex Washer Head Self Drilling Screw (commonly known as a Tek screw, metal roofing screw, hex flange drill screw, or DIN 7504K / ISO 15480 fastener) is an all-in-one structural fastener featuring a specialized drill bit tip (fluted drill point). Designed to drill its own hole, tap a mating female thread, and clamp metal structural sheets in a single continuous high-speed driving operation, it eliminates the need for pre-drilling or punching. Assembled with weather-resistant EPDM bonded washers or PVC sealing gaskets, our hex head self-drilling screws deliver leak-proof fastening for metal roofing and cladding in full accordance with global ISO standards.

Technical Specifications of Hex Washer Head Self Drilling Screws

We produce C1022A case-hardened steel self-drilling screws with drill points ranging from #2 to #5 to pierce steel purlins and heavy metal plates up to 12mm thick. The electro-deposited yellow zinc coating provides robust corrosion resistance and consistent driving performance.

Precision Manufacturing and Drill Point Forming Process

At our specialized manufacturing facility in Handan, China, hex washer head self-drilling screws undergo automated multi-station cold forming, drill point pinching, thread rolling, case-hardening heat treatment, and washer assembly:

• Hex Flange Head Cold Forming: High-speed cold heading formers press C1022A steel wire rod into precise hexagonal washer heads with sharp drive corners that prevent socket slipping.
• Precision Drill Point Pinching: High-accuracy pinching dies cut sharp cutting flutes onto the screw tip to create a perfect drill point for fast penetration.
• Thread Rolling & Pitch Control: Thread rolling machines form sharp tapping threads that follow the drill point, ensuring smooth thread engagement into drilled metal.
• Continuous Case Hardening & Tempering: Continuous mesh-belt furnaces infuse carbon into the surface layer, establishing high tip hardness (≥560 HV) to cut steel while maintaining core ductility to prevent snapping.
• Electro-Plating & Automatic Washer Assembly: Yellow zinc electroplating protects against rust, followed by automated washer assembly machines that fit EPDM or PVC washers beneath the hex flange.

Key Industrial Applications of Hex Washer Head Self Drilling Screws

Self-drilling Tek screws are essential fasteners for metal construction, roofing, HVAC, and industrial framing:

• Metal Roofing & Wall Cladding: Securing corrugated steel roofing sheets and sandwich panels to C/Z purlins with watertight EPDM washer sealing.
• Light Gauge Steel Framing & Carports: Assembling galvanized light steel wall studs, trusses, and carport framing.
• HVAC Ductwork & Solar PV Racking: Mounting air conditioning ducts, solar panel brackets, and cable tray supports to structural steel beams.

Quality Control and Export Packaging for Self Drilling Screws

Handan YiHao Fastener enforces strict Quality Assurance (QA) standards for all overseas export orders. Testing procedures include 100% drilling speed tests (drilling through standard steel plates within specified seconds), surface/core hardness testing, torque-to-fail testing, and salt spray validation.

All export items are bulk packed in heavy-duty 25kg inner cartons or 1000pcs small color boxes, neatly stacked on ISPM 15 compliant fumigated wooden pallets, and wrapped in protective stretch film for safe ocean freight.