25mm Hex Head Roofing Screw
The Generic 25mm Roofing Screw provides a high-strength fastening solution for securing metal roofing sheets to light-gauge steel purlins or timber supports. This fastener features a hardened steel construction with a protective zinc coating to resist atmospheric corrosion. The integrated EPDM washer ensures a watertight seal at the penetration point, preventing moisture ingress in industrial and residential roofing applications.
Built for the Job
This self-drilling fastener, often referred to as a TEK screw, eliminates the requirement for pre-drilling holes in metal sheets up to a specific thickness. The drill point tip cuts through the material while the following threads engage securely to provide high pull-out resistance. Contractors typically use this 25mm variant for valley fastening or when securing thin-profile cladding where longer screws would be redundant or interfere with internal structures.
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Securing corrugated iron or IBR roofing sheets to steel or timber battens.
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Fixing side-wall cladding and flashings in warehouse or shed construction.
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General purpose metal-to-metal fastening in HVAC ducting or fencing projects.
Product Highlights
- Self-Drilling TEK Point
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The engineered drill flute clears metal shavings efficiently to prevent heat buildup and ensure a clean entry.
- EPDM Sealing Washer
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- Manufactured from UV-stabilized Ethylene Propylene Diene Monomer for long-term weather resistance.
- Compresses under the hex head to form a permanent waterproof barrier against heavy rain.
Technical Specifications
| Specification | Detail |
|---|---|
| Length | 25mm |
| Head Type | 8mm (5/16″) Hex Flange |
| Material | Zinc Plated Carbon Steel |
| Washer Diameter | 14mm EPDM Bonded |
| Drill Capacity | Up to 3.5mm Steel |
What’s Included
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1 x 25mm Hex Head Self-Drilling Roofing Screw with bonded washer
On-Site & Workshop Notes
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Use a standard magnetic nut setter with a cordless impact driver for efficient installation.
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Avoid over-tightening the fastener to prevent deforming the washer, which can compromise the seal.
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Ensure the screw is driven perpendicular to the sheet surface to maintain the integrity of the EPDM gasket.
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Store in a dry environment to maintain the integrity of the zinc coating before use.

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