Rubber-Metal Composite Parts

What are rubber-metal composite parts?

Rubber-metal composite parts consist of a metallic carrier element (e.g. steel, Stainless steel or Aluminium) and a moulded or bonded rubber component. This combination unites the mechanical stability and load-bearing capacity of the metal base carrier with the elastic and damping properties of the rubber. The connection between the two materials is usually achieved by VulcanisationDuring the moulding process, the rubber is chemically cross-linked with the pre-treated metal surface under heat and pressure. This creates a permanent, inseparable bond that can withstand high forces, vibrations and environmental influences.

Typical designs:

Vibration damper and bearing bushes
Sealing and stop elements
Valve components and housing inserts
Mounting elements with press-fit or screw function

Rubber-metal composite parts are used wherever movements or forces have to be transmitted and vibrations, noise or load peaks have to be reduced at the same time. They make a significant contribution to the durability and functional reliability of complex assemblies.

Functions & applications of rubber-metal composite parts

The special combination of materials enables rubber-metal composite parts to fulfil a wide range of functions. They are used for mechanical coupling as well as for sealing, vibration insulation or energy absorption.

Functions at a glance:

Vibration dampingAbsorption and reduction of vibrations and shocks
Power transmission: elastic connection between moving and fixed components
SealingCombination of load-bearing and sealing function in one component
Mounting: Defined elastic mounting of machines, motors or components
Compensation: Compensation of manufacturing tolerances and movements
Noise reduction: Reduction of noise through vibration decoupling

Typical applications:

Mechanical and plant engineering: vibration isolators, engine mounts, machine elements with elastomer coating
Vehicle technology: axle bearings, shock absorber bushes, gearbox suspensions or exhaust mounts
Aerospace and defence industry: Vibration-isolating fasteners and sealing elements with defined stiffnesses
Medical technology: precision dampers or suspension systems for sensitive devices
Building services and energy supply: Pump bearings, valve brackets, flexible connecting elements
Electronics and sensor technology: Vibration protection for measuring systems and sensitive assemblies

Through targeted coordination of geometry, Shore hardness and material pairing, the behaviour of a rubber-metal composite part can be specifically adapted to the requirements of the respective application

Components and materials of rubber-metal composite parts

The performance of a rubber-metal composite part depends largely on the selection and combination of materials. The adhesion between the metal and elastomer is specifically optimised using adhesion promoter systems or chemical pre-treatment of the metal surface (e.g. phosphating, blasting, coating).

Metal components:

Steel: high strength, universally applicable, often galvanised or coated for corrosion protection
Stainless steelCorrosion-resistant, suitable for hygienic or aggressive environments
AluminiumLightweight and low corrosion, good for weight savings
brass or copper: good electrical conductivity, partly in electrical or hydraulic applications

Elastomer components:

NBR (nitrile rubber): oil and fuel resistant, standard material for technical applications
EPDMResistant to weathering, water and vapour, ideal for outdoor and climatic environments
NR (natural rubber): very elastic, high cushioning
FKMchemically resistant, temperature resistant up to approx. 200 °C
Siliconesoft material with excellent temperature and ageing resistance

To ensure that rubber-metal composite parts fulfil their function reliably, they are designed according to the operating conditions, e.g. shear, pressure or tensile load. The combination of shape, wall thickness and Shore hardness the dynamic behaviour is adjusted.

To ensure that rubber-metal composite parts are durable and function reliably, they have various design features that improve adhesion, load-bearing capacity, corrosion protection and ease of assembly:

Adhesion promoter layers for permanent bonding between metal and rubber
Relief or guide zones for targeted control of the deformation
Anti-corrosion coatings on the metal parts
Mounting holes or threaded inserts for direct mounting

Further entries

Crosslinking chemicals

Cross-linking chemicals ensure the permanent elasticity and dimensional stability of rubber through chemical reaction - a key component in the production of functional rubber parts.

Heat resistance

Heat-resistant materials retain their properties at high temperatures and are ideal for industrial and technical applications.

Fillers

Fillers are functional additives in rubber or plastic compounds that specifically influence mechanical properties, processability or cost structure.

Caoutchouc vs. rubber vs. elastomer

Rubber is the raw material, rubber is the end product created by vulcanisation, and elastomer is the superordinate material class of elastic polymers.

ABS: Acrylonitrile butadiene styrene

Acrylonitrile butadiene styrene (ABS) is a robust, impact-resistant and easy-to-process plastic that is used for housings, interior parts and rubber-plastic composite components with high surface and dimensional stability requirements.

Silane crosslinking

Silane crosslinking is a moisture-controlled crosslinking process for plastics and elastomers that enables mechanical stability at moderate processing temperatures.

Rubber blank

A rubber blank is a non-crosslinked, mouldable elastomer precursor that is processed in moulding tools to produce elastic rubber parts.

Sampling

In engineering, sampling is the testing and approval of sample parts of a new or revised product or manufacturing process.

Rapid tooling

Rapid tooling is the accelerated production of functional tools for the rapid production of prototypes or small series under near-series conditions.

Rubber recycling

Rubber recycling includes mechanical, thermal and chemical processes for the reuse of vulcanised rubber products as raw materials or additives in new applications.

Valve seal

A valve seal is an elastic component that reliably seals the flow of gases or liquids in a valve. The seal prevents leaks, compensates for pressure and temperature changes and ensures that the valve fulfils its switching, control or shut-off function reliably and permanently.

Plasticiser

Plasticisers are additives that make rubber and plastics more elastic and easier to process and are mainly used in flexible sealing and moulded parts.

Freeze deburring

Freeze deburring is a process for removing burrs, particularly on rubber parts, by cooling and mechanical blasting.

ISO 13485

ISO 13485 explained: an overview of the requirements, areas of application and benefits of certification for medical technology.

Rubber caps

Rubber caps reliably protect components from dust, moisture and mechanical impact.

Ageing

Ageing describes the gradual change in material properties due to external influences such as heat, UV radiation or media, which can lead to long-term impairment of function and service life.

GRP: Glass fibre reinforced plastic

GRP (glass fibre reinforced plastic) is a robust, lightweight composite material made from glass fibres and a plastic matrix that is used in a wide range of applications in industry, construction and mobility.

Deburring

Deburring is the process of removing burrs from components to ensure the function, appearance and safety of technical products.

Synthetic rubber

Synthetic rubber is an industrially manufactured elastomer material that is categorised into main chemical groups and whose properties can be specifically adapted to technical requirements.

Vulcanisation

Vulcanisation is the process in which raw rubber is converted into a permanently elastic, dimensionally stable and durable rubber state through chemical cross-linking.

Mould cavity / cavity

Mould cavities are the cavities in a mould that give the component its final geometry during the moulding process.

Primer

Primers are adhesion-promoting primers that improve the adhesion between rubber, plastic or metal and ensure a permanent bond in composite and coating applications.

Polyurethane (PU)

Polyurethane (PU) is a robust, abrasion-resistant plastic with high elasticity and chemical resistance, which is primarily used in heavily loaded technical components, dampers and composite solutions.

CFRP: Carbon fibre reinforced plastic

CFRP (carbon fibre reinforced plastic) is an ultra-light, extremely strong composite material made of carbon fibres and a plastic matrix that is used in highly stressed lightweight construction applications.

Assembly Services

Component assembly comprises the assembly of individual components into a functional unit as an assembly.

ISO 14001

ISO 14001 explained: an overview of the requirements, areas of application and benefits of the international standard for environmental management systems.

Adhesion

Adhesion is the physical holding force between two different materials at their interface and is a key factor for strong, durable connections in technology and industry.

Structural steel: S235 and S355

Structural steel (S235, S355) is a robust, easily weldable construction steel that is used as a stable carrier material in load-bearing structures, machine components and rubber-metal composite parts.

Aramid / Kevlar

Aramid / Kevlar is an extremely tensile, lightweight and heat-resistant fibre that is used as reinforcement in rubber composite parts, sealing systems and protective applications.

PES: Polyester

Polyester (PES) is a robust, chemical-resistant thermoplastic that is used both as an engineering plastic and as a fabric reinforcement in rubber composite parts.

SBR: styrene-butadiene rubber

SBR is a cost-effective, abrasion-resistant elastomer with good mechanical properties that is mainly used in tyres, seals and general moulded rubber parts.

Elongation

Elongation refers to the change in length of a material under tensile load and is a key parameter for assessing the elasticity and breaking strength of technical materials.

Calendering

Calendering is a rolling process in which rubber or plastic compounds are rolled between heated rollers. In addition to the manufacture of finished products such as rubber mats, it is primarily used in the production of rubber blanks.

FDA conformity

FDA compliance means that a material or product meets the requirements of the U.S. Food and Drug Administration and is safe for contact with food, drinking water or pharmaceutical applications. Only approved ingredients may be used and the material must not release any substances of concern into the medium.

Saturated and unsaturated polymers

Saturated polymers have only single bonds in the main chain and are resistant to ageing, while unsaturated polymers contain double bonds in the main chain and are easier to crosslink; EPDM is a speciality because its double bond is in the side chain.

Sealing lips

Sealing lips are flexible sealing elements that securely enclose media and remain reliably functional even in the event of rotation or pressure fluctuations.

Bearing bolt

A bearing pin is a cylindrical connecting element that serves as a pivot or swivel axis for moving components. It transmits forces, guides movements and secures the position of components within a bearing or a joint connection.

PPA: Polyphthalamide

Polyphthalamide (PPA) is a dimensionally stable, chemical and temperature-resistant high-performance plastic that is used in particular for precise, media-resistant components and rubber-plastic composite solutions.

Series production

Series production refers to the repeated, economical manufacture of similar components in large quantities.

Aluminium

Aluminium is a lightweight, corrosion-resistant material with high thermal conductivity that is used in a variety of ways as a construction material and support element in technical components.

Express Services

Express production refers to the particularly fast production of prototypes, tools or small batches and accelerated development projects with drastically reduced delivery times.

IIR: Butyl rubber

Butyl rubber (IIR) is a particularly gas-tight, weather- and chemical-resistant elastomer that is mainly used in tyres, seals and membranes.

FVMQ: Fluorosilicone

FVMQ is a cold-flexible, fuel- and weather-resistant fluorosilicone elastomer that is primarily used in the aviation and automotive industries for demanding sealing applications.

Suction pad

Suction cups are cup-shaped suction cups made of elastomer or plastic that cling elastically to the surface and trap the resulting vacuum. Suction cups create an adhesive connection between the gripper and the workpiece by means of negative pressure.

Peroxide crosslinking

Peroxides are reactive cross-linking chemicals that produce stable, temperature- and chemical-resistant elastomer structures without sulphur bridges in rubber processing.

Adhesion promoter

Adhesion promoters are chemical bonding agents that permanently bond rubber with other materials and thus form the basis for resilient rubber composite parts.

Rubber expansion joints

Rubber expansion joints are flexible connecting elements that compensate for movements, vibrations and pressure surges in pipework. Thanks to their elastic structure, they can absorb changes in length, lateral displacements and angular movements and thus protect connected system components from mechanical stress, vibrations and tension in the pipework system.

Elongation at break

The elongation at break indicates how much a material can stretch under tensile load before it tears.

Housing and cover with integrated seal

Housings and covers with integrated seals are components in which the sealing function is embedded directly in the plastic or metal part. The sealing function is usually realised as an overmoulded or pressed-in rubber sealing lip. They enable reliable sealing without a separate sealing component and are often used for compact, easy-to-install assemblies.

Compound

A compound is a customised material mixture of polymer and additives that is specifically tailored to the requirements of a particular technical application.

VMQ: Silicone rubber

Silicone rubber (VMQ) is a heat-, cold- and UV-resistant elastomer with very good insulation and media resistance, which is frequently used in medical, food and automotive technology.

Shore hardness

The Shore hardness measures how deeply a test pin penetrates a material and thus provides information about its degree of hardness - a decisive factor in the selection of elastic and technical materials.

Prototype construction

Prototyping is the targeted production of functional sample parts for early testing and optimisation of geometry, material behaviour and processability before the start of series production.

CAD modelling

CAD modelling is the digital design of technical components and tools that serves as the basis for production, simulation and prototype development in industry.

Outgassing

Outgassing is the escape of volatile substances from materials and can lead to malfunctions, contamination or optical faults in sensitive applications.

Rubber buffers

Rubber buffers are elastic elements that absorb and dampen shocks, oscillations and vibrations. They protect machines, devices and assemblies from mechanical loads, compensate for movements and reduce noise in technical applications.

LABS (paint wetting impairment substances)

LABS are substances that interfere with the wetting of paints and must therefore be strictly avoided or tested in paint-critical applications.

PA: Polyamide

Polyamide (PA) is a robust, wear-resistant plastic with very good strength and chemical resistance, which is used in particular in technical components and rubber-plastic composite systems.

ISO 9001

ISO 9001 is the world's most important standard for quality management. It defines how companies manage their processes so that products and services deliver consistently high quality and fulfil customer requirements.

Vibration dampers

Vibration dampers reduce vibrations and noise in machines and vehicles.

Special alloys

Speciality alloys are highly developed metal mixtures for extreme requirements in technology, medicine and industry - especially where corrosion, temperature or load limits of standard materials are exceeded.

TPE: Thermoplastic elastomers

TPEs are elastic, malleable materials with rubber-like behaviour that can be thermally processed and recycled like plastics - ideal for flexible seals, handles and hybrid parts.

Grommets

Grommets are ring- or disc-shaped protective inserts that are inserted into openings or edges to allow cables to pass through safely. Grommets protect cables and hoses from sharp edges, seal feed-throughs and can be quickly inserted into holes or gaps.

PC: Polycarbonate

Polycarbonate (PC) is a transparent, impact-resistant plastic that is used for high-quality housings, visible parts and functional composite components.

Bellows

A bellows is an elastic component with a corrugated, accordion-like geometry that absorbs movements, changes in length or swivelling movements without losing its protective or sealing function. It protects sensitive components such as joints, shafts or guides from dirt and moisture and at the same time enables a flexible, permanently movable connection.

Polymerisation

Polymerisation is the chemical reaction in which many monomers are combined to form long polymer chains - the basis for plastics and rubber elastomers.

Medical device regulation (MDR)

The Medical Device Regulation (MDR) is the central EU regulation for medical devices, which places high demands on safety, documentation and market surveillance.

Stress cracking

Stress cracking is the gradual formation of cracks in plastics due to the interaction of stress and chemical media - often with critical consequences for component safety.

Degreasing

Degreasing is an essential cleaning step for removing residues from components to ensure optimum adhesion during vulcanisation, bonding or coating.

Fatigue

Fatigue refers to the progressive degradation of material due to repeated mechanical stress and is a key factor in the design of durable technical components.

NR: Natural rubber

Natural rubber (NR) is a highly elastic, tear-resistant elastomer made from renewable raw materials that is primarily used in dynamically stressed components such as tyres, dampers and conveyor belts.

Metal oxide crosslinking

Metal oxide crosslinking is a crosslinking process that is mainly used for chloroprene rubber and produces particularly durable, ageing and flame-resistant rubber parts.

Tool costs

Tool costs are the expenses for the manufacture of tools and have a significant influence on the profitability of series production.

Vacuum cups

Suction cups are suction cups made of elastomer or plastic that cling elastically to the surface and trap the resulting vacuum. Suction cups create an adhesive connection between the gripper and the workpiece by means of negative pressure.

Burr formation

Burr formation occurs in primary forming processes due to material escaping from mould parting surfaces and joints during forming and requires targeted reworking to ensure component quality.

Rubber-fabric composite parts

Rubber-fabric composite parts are elastic components with integrated fabric inserts that ensure high tensile strength, dimensional stability and dynamic load-bearing capacity - for example in membranes, seals or conveyor belts.

PU: Polyurethane elastomer

PU elastomers are dimensionally stable, abrasion-resistant plastics with high mechanical strength that are ideal for rollers, seals and shock absorbers in heavy-duty industrial applications.

NBR: Acrylonitrile butadiene rubber

Acrylonitrile butadiene rubber (NBR) is an oil and fuel-resistant elastomer that is frequently used for seals, hoses and technical moulded parts in mechanical engineering and vehicle construction.

Vibratory finishing (barrel finishing)

Mass finishing or barrel finishing is a mechanical mass finishing process in which surfaces are machined and burrs removed using abrasive media and movement.

Elasticity

Elasticity is the ability of a material to deform under load and then return completely to its original shape - essential for flexible technical components.

Valves

Valves control, throttle or shut off liquids and gases in pipework, motors and hydraulic systems. They are crucial for process reliability and efficiency.

Keyboard and switch covers

Keyboard and switch covers are elastic protective components that protect keys and operating elements from dust, moisture and dirt. At the same time, they maintain the operating function by transmitting the actuation feel and enabling reliable sealing.

Protective housing

A protective housing encapsulates sensitive components and prevents damage caused by dirt, water or impact.

Rubber-Plastic Composite Parts

Rubber-plastic composite parts are hybrid components in which elastic and thermoplastic components are functionally combined - ideal for seals, housings and flexible technical solutions.

Sealed seats

Sealing seats are machined contact surfaces that accommodate seals in a form-fit and force-fit manner, thus ensuring permanent media separation protection.

Rubber-Metal Composite Parts

Rubber-metal composite parts are mechanically stable components in which elastomer and metal are inseparably combined - ideal for bearings, dampers and technical sealing systems.

HTV silicone: High-temperature curing solid silicone

HTV silicone is a high-temperature curing solid silicone rubber that becomes a permanently elastic material when heated. It combines high mechanical strength with excellent resistance to temperature, ageing and chemicals.

Compression moulding

Compression moulding is a process for manufacturing moulded rubber parts in which a rubber compound is compressed under pressure and heat in a closed mould and vulcanised directly.

RoHS

RoHS restricts the use of certain hazardous substances in electrical and electronic equipment in order to reduce environmental and health risks. Products may only be sold in the EU if all components comply with the specified limits for listed hazardous substances.

RTV silicone: Room temperature curing solid silicone

RTV silicone is a room temperature curing silicone rubber that cures without heat or pressure. It is particularly suitable for sealing, bonding, potting and mould making and is less strong and temperature-resistant than HTV and LSR.

FKM: Fluororubber

FKM is a heat- and chemical-resistant high-performance elastomer for seals and components in extremely demanding industrial applications.

Tensile strength

The tensile strength is the maximum stress that a material can withstand under tensile load and is a key parameter for the mechanical strength of elastomers.

Cycle time

The cycle time describes the complete duration of a production run during injection moulding or pressing and is a key parameter for efficiency and output.

Extrusion of rubber

Rubber extrusion is a continuous manufacturing process for rubber-elastic profiles, hoses and seals in which the material is pressed through a moulding die and then vulcanised.

EPDM: Ethylene propylene diene rubber

EPDM is a weather, UV and chemical-resistant elastomer with high thermal stability that is used in particular for durable seals, hoses and outdoor applications in industry and construction.

HNBR: Hydrogenated NBR

HNBR is a particularly heat-, oil- and ageing-resistant elastomer that is ideal for durable seals and technical components in dynamically stressed applications.

Engine damper

Engine dampers are elastic elements that absorb vibrations and shocks between the engine and the vehicle or machine frame. They reduce vibrations, protect adjacent components from stress and improve the noise and running behaviour of the entire system.

Seals

Seals prevent leaks in pipework, motor and system components. They also compensate for manufacturing tolerances and protect processes against pressure, temperature and media stress.

Azo and urea compounds

Azo and urea compounds are speciality chemicals that are used as blowing or cross-linking agents in rubber processing - especially for foams and friction-active components.

EN 9100

EN 9100 explained: an overview of the requirements, areas of application and benefits of certification for the aviation, aerospace and defence industries.

Molded Rubber Parts

Moulded rubber parts are elastic components made from vulcanised rubber by pressing, transfer moulding or injection moulding. They are manufactured according to drawings and are used as sealing, damping or functional elements in technical applications.

REACH

REACH is an EU regulation for the registration, evaluation and regulation of chemical substances in order to better protect people and the environment. Companies must prove the safety of the raw materials they use and inform customers if their products contain substances of concern.

Stainless steel

Stainless steel is a corrosion and temperature-resistant material that is used for durable, hygienic and mechanically resilient components in demanding technical applications.

Rebound resilience

Rebound resilience describes the ability of a material to return energy after rapid deformation - crucial for dynamic applications such as spring elements or dampers.

PP: Polypropylene

Polypropylene (PP) is a lightweight, chemical-resistant thermoplastic with a wide range of applications that is ideal for technical plastic parts and rubber-plastic composite solutions.

Glass transition temperature

The glass transition temperature (Tg) is the temperature range in which a polymer changes from elastic to glassy and largely determines its low-temperature flexibility.

Titanium

Titanium is an extremely corrosion-resistant, lightweight and high-strength material that is used in aviation, medical technology and for rubber-metal composite parts in aggressive environments.

Shaft seal

A shaft seal is a sealing element that seals between a rotating shaft and a housing. It prevents lubricants from escaping and at the same time protects against dirt, dust and moisture.

Inserts

Inserts are solid components that are embedded in rubber components during processing in order to specifically extend their functionality, stability or fastening options.

Residual materials

Residual materials are recyclable material residues from production that can be specifically collected and fed back into the production cycle to conserve resources.

brass

Brass is an easily machinable, corrosion-resistant copper-zinc alloy that is widely used as a functional and decorative metal - including in rubber-metal composite parts, fittings and electrical components.

Cold resistance

Cold resistance describes the ability of a material to remain functional and elastic at low temperatures - crucial for seals and elastomer components in outdoor or cold applications.

Injection moulding

Injection moulding is a precise moulding process for manufacturing complex plastic and rubber parts in which the material is injected into a mould under pressure and cured there.

Profile seal

A profile seal is a seal with a defined cross-sectional shape (round, rectangular, hollow or with a complex profile) that ensures a seal between two components. It is made from elastomers and is used wherever gaps, movements or unevenness need to be compensated for.