Premium M4.2-M6.3 Bonded Washers: Professional Waterproof Sealing
Our M4.2-M6.3 Bonded Washers are the industry standard for creating leak-proof connections in metal-to-metal and metal-to-wood fastening. These EPDM sealing washers consist of a metal backing permanently vulcanized to a high-quality rubber liner. When paired with self-drilling Tek screws, the rubber is compressed into the fastening hole, effectively sealing out moisture, wind, and debris. Whether you are building an industrial warehouse or installing solar arrays, our bonded washers provide a durable, weather-tight barrier.
As a leading bonded washer factory, we use 100% pure EPDM rubber to ensure long-term UV stability and ozone resistance, preventing the cracking or perishing common in cheaper neoprene alternatives.
- Exceptional Weatherproofing: The high-compression EPDM liner provides a resilient seal that withstands extreme temperature fluctuations from -40°C to +120°C.
- Corrosion Resistance: Available in 304 and 316 Stainless Steel for coastal environments and Zinc Plated Carbon Steel for standard roofing projects.
- Vibration Dampening: The rubber backing acts as a cushion, reducing noise and preventing fastener loosening in high-vibration HVAC and industrial applications.
- Uniform Compression: The metal backing ensures even pressure distribution across the rubber, preventing over-compression and tearing.
Select the correct metric sealing washer OD based on your screw head size and required coverage area.
| Thread Size | ID (Inner Dia) | Standard OD | Metal Thickness |
|---|---|---|---|
| M4.2 (#8) | 4.5 mm | 12.0 mm | 0.8 – 1.0 mm |
| M4.8 (#10) | 5.1 mm | 14.0 mm | 0.8 – 1.0 mm |
| M5.5 (#12) | 5.8 mm | 16.0 mm | 1.0 – 1.2 mm |
| M6.3 (#14) | 6.7 mm | 19.0 mm | 1.0 – 1.2 mm |
| Custom | M5 – M12 | Up to 35mm | Customizable |
Our M4.2-M6.3 EPDM Fasteners are essential for various outdoor and industrial sectors:
- Metal Roofing & Cladding: Preventing water ingress at the fastening points of corrugated sheets and sandwich panels.
- Solar Energy Systems: Ensuring watertight seals when mounting rails to residential and commercial rooftops.
- HVAC Installation: Sealing external ductwork and unit enclosures against air and moisture leaks.
- Automotive & Trailer: Used in trailer flooring and bodywork for vibration dampening and rust prevention.
Q: What is the difference between EPDM and Neoprene?
A: EPDM is far superior for outdoor use as it resists UV rays, ozone, and heat much better than Neoprene, which can become brittle and crack over time when exposed to the sun.
Q: Do you offer large OD washers for polycarbonate roofing?
A: Yes, we provide Large OD Bonded Washers (up to 25mm or 29mm) designed specifically for spreading the load on soft or fragile roofing materials.
Source M4.2-M6.3 Bonded Washers from a Professional Supplier
Seeking bulk EPDM sealing washers with guaranteed UV stability and competitive pricing? We support global wholesale and custom packaging. Contact us today for a free quote and technical samples!
