Rubber to metal bonding is a specialized manufacturing technique that permanently combines elastomers with metal substrates to create strong, unified parts. This approach allows manufacturers to take advantage of the strength and durability of metal while also adding the flexibility, sealing capability, and vibration absorption of rubber.
At Jefferson Rubber Works, we focus on delivering rubber-to-metal bonded products that meet tight tolerances, withstand challenging environments, and support critical applications across industries. With decades of experience, we help customers achieve reliable performance where ordinary assembly methods fall short.
Process
Glue
One way to join rubber and metal is by gluing molded elastomer parts to a finished metal component. This secondary process is performed after the rubber and metal parts have been manufactured, using an adhesive chosen for the materials and application.
Because gluing does not create as strong a bond as molding, it is best suited for certain conditions:
- Non-machined castings. Cast metal parts often have looser tolerances that make them difficult to fit securely in a mold.
- Welded inserts. When an insert includes welded joints and precision welding is not practical from a cost perspective, the dimensional variation from welding can prevent the insert from fitting correctly in the rubber mold. In these situations, adhesives can provide a practical alternative to avoid potential damage to the inserts or mold.
- Controlled environments. Parts that are not exposed to harsh weather, chemicals, or water can often be assembled more efficiently with glue than with full insert molding.
While gluing is more labor-intensive and the bond strength depends heavily on the adhesive, it can be the most efficient option for applications where precision tolerances and environmental durability are not the primary requirements.
Bonding
With rubber to metal bonding, the elastomer is molded directly onto a prepared metal insert. The process begins by cleaning the insert through chemical treatments, grit blasting, or degreasing to remove oils, oxides, and other contaminants. A heat-activated adhesive is then applied by spraying, dipping, or by hand. Thickness is carefully controlled to ensure uniform coverage.
The prepared inserts are placed into the mold cavities and secured in position. Rubber is introduced by injection, transfer, or compression molding, where heat and pressure vulcanize the elastomer while activating the adhesive. This creates a permanent molecular bond between the rubber and the metal.
Our Steps
At Jefferson Rubber Works, every project follows a structured bonding process. The key steps include:
- Surface preparation. Metals are cleaned with degreasing, grit blasting, or chemical treatments to remove contaminants.
- Primer and adhesive application. A heat-activated adhesive or primer is evenly applied to create a chemical bridge between the metal and rubber.
- Placement in mold. Inserts are accurately positioned in the mold, often held with magnets or chaplet pins for stability.
- Molding and curing. Rubber is molded by injection, transfer, or compression methods, wherein heat and pressure cure the elastomer and activate the adhesive.
- Demolding and post-processing. Finished parts are removed, inspected, and may undergo trimming or other finishing operations to meet final specifications.
- Testing and inspection. Products are checked for adhesion, bond strength, dimensional accuracy, and performance under simulated conditions.
Rubber to Metal Bonding Applications
Because bonded components combine the best qualities of rubber and metal, they are used across industries that need strength, flexibility, and resilience in one product. Common examples include:
- Automotive: Suspension bushings, engine mounts, exhaust hangers, vibration isolators, seals, and brake system components.
- Aerospace: Couplings, landing gear seals, noise reduction components, and vibration dampers.
- Industrial equipment: Anti-vibration pads, pump and compressor seals, flexible couplings, and conveyor rollers.
- Electronics: Grommets, connectors, cable assemblies, and EMI/RFI shielding.
- Medical devices: Instrument grips, diaphragms, precision seals, and medical-grade gaskets.
- Construction: Expansion joints, waterproof gaskets, vibration control mounts, and pipe supports.
Rubber to Metal Bonding With Jefferson Rubber Works
Jefferson Rubber Works provides complete rubber to metal bonding services for manufacturers who need precise, long-lasting components. Our facilities are ISO 9001:2015 certified, ITAR-registered, and FDA-registered, with additional ISO 13485 certification for medical device manufacturing.
By combining advanced molding techniques with stringent quality controls, we deliver bonded parts that meet exact specifications. All manufacturing takes place in the United States, giving customers confidence in lead times, compliance, and product reliability.
For more information about our rubber to metal bonding capabilities, contact us today.