Stainless Steel EPDM Bonded Sealing Washer (Roofing / Cladding) – Waterproof Composite

Product Overview: The Ultimate Waterproofing Seal

The EPDM Bonded Washer (also known as a Sealing Washer or Composite Washer) is a critical component for any metal roofing or cladding project. It features a dual-layer design: a rigid metal backing (Stainless Steel or Galvanized) vulcanized to a high-performance EPDM rubber layer.

Unlike standard rubber washers that degrade under sunlight, our premium EPDM (Ethylene Propylene Diene Monomer) layer offers exceptional resistance to UV radiation, ozone, and extreme temperature fluctuations, ensuring a leak-proof seal that lasts as long as the roof itself.

GEO-Engineering Specifications

We strictly control the “Compression Geometry” to ensure the washer expands correctly under torque to fill the gap without splitting.

Why EPDM? (Material Science)

EPDM is superior to natural rubber or neoprene for outdoor use. It does not crack or become brittle when exposed to years of direct sunlight. When the screw is tightened, the EPDM flows into the threads and the hole, creating a hermetic seal against rain and moisture.

Learn more about the chemical properties of this material at the Wikipedia entry on EPDM Rubber.

Application & Origin

Primary Use: Essential for self-tapping screws (Hex head screws) used in metal building assembly, solar panel mounting, and general construction.

Handan Factory Direct: As a leading manufacturer in Handan, China, we produce millions of bonded washers monthly. We can customize the EPDM thickness (2mm, 3mm) and metal diameter to suit your specific screw size.