Understand EPDM Bonded Washers in One Article: A Detailed Explanation of Process and Operating Condition Adaptation
For outdoor fastening applications including metal roof and solar projects, sealing failure is one of the most common failure causes.Many customers initially select ordinary separate rubber gaskets and flat washers. Under complex outdoor working conditions such as salt-spray corrosion, strong UV radiation, alternating high-low temperature, ordinary rubber gaskets will crack, harden and leak after short-term service.
EPDM Bonded Washers, also known as EPDM Roof Washers, adopt integrated high-temperature vulcanized metal-rubber composite structure. Precision-stamped metal substrate and high-performance EPDM rubber layer achieve molecular-level bonding through high-temperature vulcanization. It is one-piece component without separate field assembly. Rigid metal substrate bears screw tightening pressure to prevent rubber over-crushing. EPDM rubber layer delivers stable compression resilience and fits closely against sheet surface for long-term waterproof and weather-resistant sealing, fundamentally avoiding sealing risks caused by split gaskets.
1. Product Structure, Material & Surface Process
1.1 Metal SubstrateAvailable materials
Galvanized steel, stainless steel, aluminum, copper. Precision-stamped sheet, thickness 0.5-1.2 mm. Retain original anti-corrosion property, secondary coating is unnecessary for most applications. Provide rigid mechanical support and disperse screw tightening load.
1.2 EPDM Rubber Sealing LayerBase grade
High-performance EPDM. Optional grades: thermoset EPDM, conductive EPDM for grounding, neoprene. Rubber thickness:1.5-5 mm. Multiple colors: black, gray, red, green, blue for building facade matching. Rubber features heat-resistance, waterproof, anti-UV and anti-ozone property, anti-aging for long-term outdoor service.
1.3 High-temperature Vulcanization Craft
Not simple physical sticking, realize molecular-level bonding between metal and rubber. Effectively avoid delamination, bubbling and peeling under continuous vibration & thermal cycles, maintain sealing integrity.
2. Stock & Custom Scope
★ Black star: Normal standard stock items；● Red Spots: Special non-standard customized products.
Parameter Item
Specification
Metal Substrate Thickness
0.5-1.2 mm
Rubber Layer Thickness
1.5-5 mm
Rubber Color Option
Black, Gray, Red, Green, Blue
Long-term Operating Temperature
-30 ℃ ~ +120 ℃
Performance Comparison：Ordinary Rubber Washer VS Metal-EPDM Bonded Washer
Performance Item
Ordinary Rubber Washer
Metal-EPDM Bonded Washer
Salt-spray Resistance
Poor, rubber ages fast under coastal salt-fog
Excellent performance, suitable for long-term coastal & offshore projects
Anti-UV & Anti-ozone
Weak resistance, crack & resilience loss under outdoor exposure
Outstanding UV & ozone resistance, no cracking after years of outdoor service
Temperature Adaptability
-10 ℃ ~ +70 ℃, brittle in cold, over-soften in hot environment
-30 ℃ ~ +120 ℃, stable elasticity under sharp temperature fluctuation
Compression Performance
No rigid support, permanent deformation caused by over-tightening
Metal substrate shares tightening load, rubber keeps proper compression ratio
On-site Assembly
Two-piece separate parts, easy offset during installation
One-piece integrated part, fast installation without dislocation risk
Life-cycle Cost
Short service life, regular inspection & frequent replacement required
Extended service cycle, greatly reduce later-stage rework & maintenance cost
3. Condition Value
Large compression force generates while tightening self-drilling screws on metal roof panels and solar brackets. Split ordinary rubber gaskets are easy to crush. Once gaskets shift, rainwater infiltrates through fastener gaps. Leakage risk is hidden and can only be found in rainy days.
One-piece Metal-EPDM bonded washers solve this pain point. Metal layer absorbs mechanical pressure; EPDM rubber fits profile surface tightly to block rainwater and dew penetration. Standard sizes in-stock for fast delivery. Custom thickness, bore size and rubber formula are available per drawings or samples for special project requirements.
If you are troubled by outdoor fastener-point leakage and gasket aging failure, please contact our engineering team for datasheets, sample testing and professional sealing selection suggestions.
