Hex Bolt with Rubber Washer - Durable, Leak-Proof Fasteners
Product Overview
Fasto hex bolts with rubber washers (also referred to as sealing bolts or gasketed bolts) are engineered to meet DIN 933, ISO 4017, and DIN 931 industrial standards. By integrating a high-performance elastomeric washer, these fasteners create a high-pressure seal that prevents fluid ingress and protects delicate substrates from mechanical scratches or compression damage. They are ideal for solar mounting, HVAC installations, and outdoor enclosure assemblies.
Technical Specifications
Technical Advisory: For specifications M16 and above, Fasto highly recommends the use of metal-backed Bonded Washers. This configuration prevents rubber extrusion under high installation torque, ensuring long-term seal integrity.
Product Parameters
| Product Name | Alias | Material | Specification |
| Hex Bolt with Washer | Sealing Hex Bolt |
SS304/316 + EPDM |
M5 - M24 |
| Gasketed Bolt | Anti-Vibration Bolt | Stainless Steel + NBR | 10mm - 200mm |
Applications
Why Choose Fasto?
Fasto Industrial operates dedicated manufacturing plants with over 20 years of export experience. Our production processes are managed under IATF 16949 and ISO 9001 systems, guaranteeing that every fastener shipment stays within narrow technical tolerances. We provide customers with full verification data, including CE, SGS, and RoHS certificates, which ensures compliance with global construction and environmental regulations.
Our engineering team focuses on structural reliability and application-specific logic. By matching austenitic stainless steel bodies with industrial-grade EPDM or NBR sealing components, we offer fastening solutions that prevent galvanic corrosion and fluid leaks. Fasto’s commitment to quality control ensures that every bolt provides the specified load-bearing capacity and sealing performance required for high-exposure building envelopes and industrial machinery.
FAQ
Q: Should I choose EPDM or NBR for my application?
A: EPDM is the industry standard for outdoor applications due to its excellent UV and ozone resistance. NBR is preferred for mechanical environments where the fastener may come into contact with oils, fuels, or lubricants.
Q: Why is a bonded washer recommended for M16+ sizes?
A: Larger bolts require higher torque to achieve proper clamping force. A standard rubber washer may extrude or deform under these loads. A metal-backed bonded washer distributes the pressure, preventing extrusion while maintaining a permanent seal.
Q: Can these bolts be used in marine environments?
A: Yes, we recommend using SS316 (A4) grade hex bolts for coastal and marine projects. When paired with high-grade EPDM washers, they provide superior protection against salt spray and chloride-induced corrosion.
Q: Is pre-drilling required for these hex bolts?
A: Yes, unlike self-drilling screws, these hex bolts are machine-threaded and must be installed into pre-drilled and tapped holes, or used with a corresponding nut and washer set.