EPDM Rubber Washers — Complete Guide
EPDM (ethylene propylene diene monomer) rubber washers are the go-to choice for outdoor, roofing, and water-contact applications. EPDM offers outstanding resistance to weathering, UV, ozone, and steam — properties that most other rubber materials can't match.
EPDM Washer Properties
- Temperature range: -65°F to +300°F (-54°C to +149°C)
- Weather/UV/ozone resistance: Excellent — best of all common rubbers
- Water and steam resistance: Excellent
- Oil resistance: Poor — not suitable for oil contact
- Chemical resistance: Good for dilute acids, alkalis, ketones
Best Applications for EPDM Washers
- Roofing and skylight fasteners
- Outdoor and exposed hardware
- Potable water systems (NSF-compliant grades available)
- Steam lines and hot water plumbing
- Window and door sealing
- Solar panel mounting systems
When Not to Use EPDM
EPDM is not compatible with petroleum oils, fuels, or hydrocarbon solvents. For oil-contact applications, use Nitrile (Buna-N) washers instead.