Hex Washer Head Self-Drilling Screw with EPDM Washer
The classic roof and cladding fastener. Bonded EPDM rubber washer creates a watertight seal.
Specification
| Head | Hex washer with bonded EPDM seal |
|---|---|
| Drive | Hex 5/16" or 8 mm |
| Point | Self-drilling |
| Finish | Zinc plated |
| Diameter | 5.5 – 6.3 mm |
| Length | 19 – 100 mm |
| Standards | DIN 7504K, ASTM C954 |
| Material | SAE 1022 hardened carbon steel, bi-metal options |
Custom sizes, finishes and OEM packaging available. Samples shipped within 5 working days of approval.
Why it is built this way
Engineering notes
Every metal roof on earth is held down by some version of this screw. The hex washer head takes a nut driver, so the installer works from a socket rather than a bit that can cam out at the top of a ladder. Under it, an EPDM washer vulcanised to a steel cap compresses into the panel rib and turns the penetration back into a seal.
The bonded construction is what separates it from a loose washer. A free rubber washer squeezes out sideways under the head and loses its compression within a season; a bonded one is held captive by the cap, so the seal stays under load through years of thermal cycling.
Key features
- EPDM washer vulcanised to a steel cap for captive compression
- Hex drive worked with a socket, not a cam-out-prone bit
- Self-drilling point for direct fixing into purlins
- The highest-volume fastener in the roofing family
Typical applications
- Metal roof panels
- Steel cladding
- Agricultural buildings
- Warehouses & sheds
- Carports
- Industrial roofing
Buyer questions
Frequently asked
How tight should the screw be driven?
How long does an EPDM seal last?
Is a larger washer available?
Related technical guides
- How an EPDM Bonded Washer Seals a Roof Penetration
- SAE 1018, 1022 and 10B21: Fastener Steel Grades Explained
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Quote Hex Washer Head Self-Drilling Screw with EPDM Washer
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