Motorcycle Modified Windshield Rubber Brass Well Nuts: 10-Piece Set in M4, M5 & M6 Sizes

Securing accessories, windshields, and fairings on a modified motorcycle often requires creating robust mounting points in thin or inaccessible panels. This 10-piece set of rubber brass well nuts, available in M4, M5, and M6 metric thread sizes, provides a practical solution. These expansion fasteners combine a black rubber body with an integrated brass insert nut. They are designed to be installed from one side only, compressing to form a vibration-dampening, water-resistant seal in sheet metal, plastic, or fibreglass. This makes them particularly useful for custom projects, repairs, or adding aftermarket parts where a conventional nut and bolt cannot be used.

Features and Construction

The G388 series well nuts are built for durability and reliable performance in vehicle applications. Their two-material construction addresses common issues like corrosion, vibration loosening, and water ingress.

Material and Build

Each fastener consists of two key components. The threaded connection point is a brass insert nut, chosen for its resistance to corrosion and ability to maintain strong threads. The main body is made from black rubber, which is designed to expand and compress. When the fastener is tightened, this rubber body flares out behind the panel and contracts around the front, creating a firm grip and a compression seal that blocks moisture and dampens vibrations from the engine and road.

Size and Practical Fit

The set is offered in three distinct metric thread sizes to match different bolt and screw requirements: M4, M5, and M6. The external diameter of the rubber body corresponds to the drill hole size needed: 11mm for M4, 12mm for M5, and 13mm for M6. The M6 size features a slightly larger 13.6mm flange diameter for increased bearing surface. All fasteners in the pack are of a single chosen size, providing consistency for a specific project.

Uses and Placement

These well nuts are versatile for various automotive and DIY tasks but are explicitly noted for motorcycle modification. Their one-sided installation is a key advantage in confined spaces.

Event or Professional Use

For motorcycle customisation shops or enthusiasts undertaking modifications, these fasteners are ideal for mounting aftermarket windshields, fairing panels, indicator lights, or small accessory brackets. They allow for secure attachment in fibreglass or ABS plastic fairings where adding a backing plate or nut is impossible. The seal they create helps prevent water from entering through mounting holes, protecting electrical connections or interior spaces.

Everyday Home Use

Beyond motorcycles, these well nuts are useful for general DIY, marine applications, or securing items to hollow-core doors, caravan panels, or metal cabinets. Any scenario requiring a sturdy, sealed fastening point in a thin material without rear access can benefit from this design. The vibration-dampening quality also makes them suitable for mounting number plates or panels that are subject to constant movement.

Benefits and Buying Value

The value of this product lies in its specialised design solving a specific problem, its durable material choice, and the convenience of a 10-piece pack.

Reuse and Low Maintenance

While designed for permanent installation, the brass thread is durable and can be reused if the fastener is carefully removed. The rubber seal may lose some effectiveness after disassembly. Once installed, the materials require no maintenance; the brass resists corrosion, and the rubber does not need treatment. This provides a long-term, reliable mounting solution that won't loosen over time like a standard bolt and nut might.

Why Choose This Product

Choosing this specific set provides a ready supply of specialised fasteners matched to common metric thread sizes used in motorcycle and automotive contexts. The combination of brass and rubber is purpose-selected for outdoor, high-vibration environments. Having 10 pieces means you have spares for multiple mounting points or future projects, offering better value than buying singles. It directly addresses the need for a sealed, one-sided fastener that is both strong and gentle on delicate panels.