Groxx Annular Cutter
The Groxx Zinc-Coated Hex Self-Drilling Roofing Screw (Model Number: GGRXRFS4875) is a premium, contractor-grade structural fastener designed for securing metal roofing profiles, siding, and trapezoidal sheets directly to timber or light-gauge steel purlins. Engineered with a self-drilling point and a high-efficiency sealing system, this screw eliminates the need for pre-drilling while guaranteeing long-term watertight performance and robust wind-load resistance.
Advanced Self-Drilling Tip: Equipped with an engineered drill point (Type #3/DIN 7504-K style) that cleanly pierces metal sheets and purlins in a single, high-speed operation, eliminating separate pilot hole-drilling stages.
Corrosion-Resistant Zinc Shielding: Treated with a high-purity electro-galvanized zinc coating. This sacrificial barrier delivers excellent resistance against red rust, moisture tracking, and chemical weathering.
Watertight EPDM Bonding Washer: Pre-assembled with an aluminum-backed EPDM (Ethylene Propylene Diene Monomer) rubber washer. The washer compresses evenly upon driving to form an absolute weather-tight seal against heavy rain, atmospheric moisture, and thermal expansion cycles.
Hex-Washer Drive Stability: Features an integrated hexagonal washer head to ensure slip-free driving torque and broad load-bearing distribution across the fastened sheet profile.
| Feature / Dimensional Parameter | Engineering Value / Standard |
| Model Number | GGRXRFS4875 |
| Screw Type | Hex Washer Head Self-Drilling Roofing Screw |
| Nominal Outer Diameter ($D$) | 4.8 millimeters |
| Total Length ($L$) | 75.0 millimeters |
| Material Base | Hardened Carbon Steel (Grade SAE J403 1022 or equivalent) |
| Surface Treatment / Coating | Electro-Plated Zinc Coating (Bright Zinc-Plated) |
| Drive Interface | 8.0 mm Hex Head ($s = 8\text{ mm}$ Spanner size) |
| Head Thickness ($k$) | Approximately 4.3 mm |
| Flange Head Diameter ($dk$) | Approximately 10.0 mm |
| Washer Assembly | Pre-fitted EPDM / Aluminum Backed Sealing Washer |
| Recommended Driving Speed | 1,500 RPM to 2,500 RPM |
Tested under rigid industrial fastener guidelines (simulating vertical shear and axial tensile strain over structural sheet profiles):
Ultimate Tensile Resistance: 7.11 kilonewtons ($7.11\text{ kN}$ / approx. 725 kg of pull-apart resistance)
Ultimate Shear Resistance: 3.56 kilonewtons ($3.56\text{ kN}$ / approx. 363 kg of perpendicular force tolerance)
Metal to Timber / Steel Framing: Securing corrugated roofing sheets and cladding panels down to timber battens or thin metal purlins up to 2.5 mm thickness.
Overlapping / Stitching Profiles: High-strength stitching of overlapping steel sheets along structural roof ridges and side seams.
Industrial Warehousing: Erecting rain screens, cold-storage walls, and prefabricated agricultural sheds.
Eliminates On-Site Pre-Drilling: Combining the drilling, thread-tapping, and tightening phases into one fluid step cuts installation times by up to 50% compared to traditional fastener methods.
Zero Leakage Sealing Technology: The premium EPDM composite washer will not dry-rot, crack, or squeeze out of shape under high driving torque, keeping the fastening point completely waterproof for years to come.
Flawless Torque Engagement: The deep, precision-formed 8 mm hexagonal socket head prevents the driving bit from slipping or spinning out, saving your panel finish from scratches and keeping installation fast and safe.
