Premium Rubber Well Nuts | Metric & Imperial Expanding Nuts Kit
- 100% Watertight Seal: Marine-grade Neoprene/EPDM rubber prevents all water and dust leaks.
- Full Size Selection: Complete range of Metric (M3-M8) and Imperial (#6-32 to 3/8″) in stock.
- Shock & Vibration Proof: Absorbs heavy impacts to protect fragile plastic parts from cracking.
- Factory Wholesale: Direct pricing with customizable metal inserts and flexible packaging options.
What is A Well Nut?
Well Nuts (also known as rubber expansion nuts or expanding nuts) share a similar principle with rivet nuts and are blind fasteners specially designed for single-side operations. The exterior is wrapped in a rubber coating, and the interior features precision threads. Upon tightening the screw, the rubber expands under pressure, forming an ultra-strong dynamic seal to achieve excellent waterproof and dustproof performance.
The Well Nuts supplied by T&Y are manufactured from 100% pure rubber compounds, which strongly resist UV rays, ozone, and saltwater corrosion, completely preventing premature cracking or aging. We implement strict quality control standards, support low MOQ orders and in-depth factory customization, comprehensively meeting various business needs to provide you with trustworthy, long-term, and reliable assurance.
| Product Feature | Specifications |
| External Material | Neoprene / EPDM Rubber |
| Internal Material | Stainless Steel / Brass (Other metals can be customized) |
| Metric Sizes | M3, M4, M5, M6, M8 |
| Imperial Sizes | #6-32, #8-32, #10-24, #10-32, 1/4″-20, 5/16″, 3/8″ |
| Main Applications | Kayaks & Marine, Motorcycles (Windshields/Fairings), Automotive, Fiberglass & Plastics, HVAC & Machinery |
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It works by mechanical compression. When you tighten the bolt, it pulls the internal metal core upward. This action forces the rubber sleeve to bulge out behind the panel, forming a secure collar that locks the parts together while dampening vibrations.
Well nuts provide reliable light-to-medium holding strength. They are not designed for heavy structural loads, but they give strong pull-out and shear resistance on thin or fragile materials like fiberglass, plastics, and sheet metal. Their flexible design prevents the base material from cracking under stress, which is perfect for high-vibration environments.
Drill a hole matching the outer diameter of the rubber sleeve and press the well nut in until the flange sits flush against the surface. Then, align your fixture, insert a matching machine screw, and tighten it until the rubber expands firmly behind the panel, making sure not to over-torque.
Yes! Unlike standard metal rivet nuts that undergo permanent deformation, well nuts are made of flexible, elastic rubber. When you unscrew the bolt, the rubber sleeve returns to its original shape, allowing you to remove and reuse it multiple times without damaging the hole.
No. T&Y well nuts feature precision-machined, standard metric and imperial threads inside the metal core. They must be paired with standard machine screws or bolts. Using sharp self-tapping screws will strip and ruin the internal metal threads.
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