Silicone Rubber for Aerospace Applications: Emerging Trends and Key Considerations

Selecting silicone rubber for an aircraft or aerospace component is not only about finding a material that can handle high temperatures. A part may face heat and cold, vibration, pressure changes, moisture, sunlight, or contact with fluids during its service life. In many cases, it has to handle several of these conditions at once.

For engineers and OEMs, the application should therefore guide the material choice. Silicone grade and hardness matter, but so do the component's size, sealing conditions, manufacturing method, required specifications, and testing needs.

As an aerospace silicone rubber manufacturer in the USA, Elastostar Rubber Corporation manufactures custom seals, gaskets, O-rings, tubing, extruded profiles, and molded silicone components for aerospace applications.

The wider silicone elastomers market is also changing as demand grows across automotive, healthcare, electronics, transportation as well as other industries. According to Coherent Market Insights (CMI), the global silicone elastomers market is estimated at US$5.59 billion in 2026 and is expected to reach US$8.7 billion by 2033, growing at a CAGR of 7.5% during the forecast period. CMI covers the market by product type, application, end-user industry, and geography.

Three trends are especially relevant to aerospace and other demanding applications. First, manufacturers are developing silicone elastomers with better heat resistance, durability, and electrical insulation. This is useful in parts that must keep working under demanding conditions. Second, electric vehicles and advanced electronics are increasing the need for materials that can provide thermal management as well as electrical protection. The same material improvements can also support other high-performance applications.

Third, silicone manufacturers are paying more attention to sustainable materials and newer production methods, including additive manufacturing. These changes are giving manufacturers more ways to produce customized parts as well as reduce development time.

The CMI report places Liquid Silicone Rubber (LSR), High Consistency Rubber (HCR), Foam Silicone, Gum Silicone, and other silicone elastomers under product type. By application, it covers automotive, healthcare, electronics, consumer goods, industrial applications, and others. By end-user industry, it includes transportation, medical devices, electrical and electronics, construction, personal care, and others. This wide market structure is useful when looking at aerospace silicone because it shows how material requirements can change from one application to another.

Why Material Selection Matters in Aerospace Applications

An aerospace rubber component rarely has only one job to do. A gasket may need to stay flexible as temperatures rise and fall while also maintaining enough compression to create a reliable seal. Another component may have to handle vibration, moisture, pressure changes, or outdoor exposure.

Location matters as well. A static gasket installed between two fixed surfaces does not face the same demands as a seal that moves during operation. A component exposed to fuel, oil, hydraulic fluid, or cleaning chemicals also needs different consideration from one working in a dry environment.

This is why temperature resistance alone does not provide enough information to choose an aerospace silicone. Engineers need to consider what will actually happen to the finished component during service.

The same point can be seen in the wider silicone elastomers market. CMI identifies automotive as the largest application, while healthcare is the fastest-growing application. Silicone elastomers are used in automotive components, medical devices, electronic parts, consumer products, and industrial applications because they can combine flexibility with resistance to heat and environmental conditions.

Automotive is particularly important because silicone elastomers are increasingly used in electric vehicles, including battery systems and thermal management components. These applications need materials that can handle heat while also providing insulation and long-term stability. The growth of EV production is therefore supporting demand for more specialized silicone elastomers.

1. Understand the Application Requirements

Before choosing an aerospace grade silicone rubber, look at the conditions the finished part will actually face. Temperature is one consideration, but it is rarely the only one. Pressure, vibration, movement, moisture, ozone, UV exposure, and outdoor conditions may also affect performance.

Fluid exposure deserves attention as well. If the part will come into contact with fuel, oil, hydraulic fluid, cleaning agents, or other chemicals, compatibility should be checked before settling on a silicone grade.

It is also important to know how the component will work once installed. A gasket held between two fixed surfaces has different demands from a seal that moves during operation. Hardness, compression, dimensions, and expected service life should therefore be considered together.

This application-based approach also explains why different silicone elastomer products serve different markets. LSR, for example, is widely used where precise molding and consistent part production are needed. HCR is commonly used for extrusion and molding where mechanical strength and durability are important. CMI identifies LSR as the largest product type, with a 43% market share, supported by its use in automotive, healthcare, and electronics applications.

Static vs. Dynamic Sealing

A static seal remains between surfaces that are not intended to move relative to each other. In this type of application, the seal must maintain contact over time. Compression set, groove dimensions, sealing force, and long-term compression are therefore important.

Dynamic service introduces movement. Friction and wear then become part of the equation, along with speed, lubrication, and the condition of the mating surface.

Knowing whether the seal will remain stationary or move in service helps narrow the choice of material, hardness, and seal design.

2. Evaluate Silicone Rubber Performance

Silicone is used for many aerospace components because it remains flexible through a broad range of operating conditions and holds up well against environmental aging. Still, those qualities alone do not determine whether a particular silicone is right for a part.

Temperature Resistance

Temperature ratings are a useful starting point, but they are not the whole answer. The same silicone can behave differently depending on how long it is exposed to heat or cold and what mechanical loads or fluids are present at the same time.

For this reason, the expected service temperature should be reviewed alongside the actual working conditions. A value shown on a material data sheet should not be the only basis for approving an aerospace component.

Compression Set and Flexibility

For seals, gaskets, and O-rings that remain compressed for long periods, recovery after compression can be particularly important. If the material loses too much of its original shape, maintaining sealing contact may become difficult.

Hardness, cross-section, temperature, and the amount of squeeze all influence this behavior. These factors are better considered together rather than treating compression set as an isolated material property.

Fluid and Chemical Compatibility

Standard silicone does not suit every fluid environment found in aerospace equipment. Fuel, oils, hydraulic fluids, lubricants, cleaning agents, and other chemicals can affect elastomers differently.

The actual fluid, concentration, temperature, and exposure conditions should be known before material approval. Where resistance to fuels or oils is required, FVMQ, or fluorosilicone, may be considered, subject to the requirements of the application.

3. Select the Right Silicone Grade

There is no universal silicone grade for aerospace use. What works for one component may be unsuitable for another, even when both parts are used on the same aircraft or system.

The drawing and application requirements are usually the best place to start. They may identify a particular material specification, hardness, class, or performance requirement that limits the available choices.

General-Purpose vs. Aerospace Specification Materials

Some components can use commercially specified silicone, while others must conform to an aerospace, military, OEM, or customer specification.

A-A-59588, for example, covers silicone rubber materials with different classes and grades. If a drawing calls for a particular specification, the required class, grade, and other applicable details should be confirmed before the material is ordered or production begins.

This avoids selecting a silicone simply because its general properties appear suitable.

HCR, LSR, and Specialty Silicone

The intended manufacturing process can also affect material choice. HCR (High Consistency Rubber) is commonly used for extrusion and molding, while LSR (Liquid Silicone Rubber) is associated with liquid injection molding.

LSR is an important sub-segment in the wider silicone elastomers market. CMI estimates that it holds 43% of the product-type segment in 2026. Its ability to support precise injection molding makes it useful for products with detailed shapes and consistent dimensions. Applications include automotive parts, medical components, electronics, and other molded products. Demand for LSR is also supported by the need for durable materials that can handle heat and, in some healthcare applications, meet biocompatibility requirements.

For aerospace parts, the choice between HCR, LSR, and another silicone formulation should still depend on the actual component. A molded seal, an extruded profile, and a small precision component may require different materials and manufacturing methods.

Other formulations may be required when a component has specific electrical, flame, environmental, temperature, or mechanical requirements.

Material selection and manufacturing method should therefore be considered together, particularly for custom components.

Selecting the Right Hardness

Hardness affects how readily a silicone part deforms when force is applied. A softer compound generally conforms more easily, while a harder compound offers greater resistance to deformation.

Neither characteristic makes a material automatically suitable for a particular seal. The required hardness depends on the part geometry, available compression, installation method, mating surfaces as well as operating conditions.

4. Review Aerospace Standards and Quality Requirements

Aerospace projects often come with requirements that extend beyond basic material properties. Depending on the component, these may include SAE/AMS specifications, A-A-59588, ASTM test methods, OEM requirements, customer specifications, or engineering drawings.

These documents should be reviewed early because they may define the material, hardness, tolerances, testing, inspection, or documentation expected for the finished part.

The manufacturer's quality system is a separate consideration. AS9100D provides a framework for controlling aerospace manufacturing processes, including traceability, risk management, documentation, and quality controls. It does not replace the material specification called out for a component.

When requesting a quote, engineers can reduce uncertainty by providing the applicable specification and revision together with the drawing, dimensions, tolerances, hardness, testing needs, and documentation requirements.

5. Consider Part Design and Manufacturing

Material properties tell only part of the story. A component also has to be manufactured to the required shape and dimensions.

A thin-wall tube, an extruded profile, a large sealing ring, and a molded gasket present very different manufacturing considerations. Cross-section, wall thickness, tolerances, sealing surfaces, and overall geometry can influence how consistently a part can be produced.

Aerospace Component	Manufacturing Considerations
Silicone seals and profiles	Cross-section and extrusion geometry
Silicone O-rings	Diameter, cross-section, groove fit, and construction method
Silicone gaskets	Thickness, profile, sealing surface, and dimensional accuracy
Molded components	Tooling, geometry, tolerances, and required quantity
Silicone tubing	ID, OD, wall thickness, and flexibility
Large sealing rings	Diameter, cross-section, and vulcanized joint quality

Manufacturability is worth discussing before the design is finalized. A small change to a tolerance, corner, wall thickness, or profile can sometimes make a significant difference to how reliably a custom rubber component can be produced.

This is also where the growth of silicone elastomers in transportation becomes relevant. Transportation is the largest end-user industry in the CMI report, supported largely by automotive demand. According to Coherent Market Insights, transportation segment is slated to account for a market share of 40% in 2026.

Silicone elastomers are used in seals, gaskets, thermal management parts, and other vehicle components. Their use in EV systems is adding another area of demand because battery and electrical systems need materials that can handle heat and provide insulation.

For aerospace manufacturers, the same basic lesson applies: the material needs to work with the part design and the manufacturing process, not just meet a general performance description.

6. Evaluate the Aerospace Silicone Rubber Manufacturer

Material availability and price are important when sourcing aerospace rubber parts, but they do not tell buyers much about how a supplier will handle a custom project.

Look at the work the manufacturer can actually support. This may include custom extrusion and molding, dimensional inspection, material traceability, prototype development, reverse engineering, documentation, and repeat production.

For custom parts, the information available at the start of the project also matters. A detailed drawing is useful, but it is not always available. Existing samples, CAD files, dimensions, material specifications, and application details can also provide a starting point.

The aim is to make sure the manufacturer understands both the material requirement and how the finished component will be produced and inspected.

The wider market includes established silicone producers such as Shin-Etsu Chemical, Wacker Chemie, Dow Silicones, Momentive Performance Materials, Elkem, KCC Corporation, Nusil Technology, Grace Silicone, Bluestar Silicones, and Kaneka. These companies supply silicone materials and develop products for areas such as automotive, healthcare, electronics, and industrial applications. Their activity also reflects the broader move toward specialized grades and application-specific silicone solutions.

Regionally, Asia Pacific is expected to dominate the global silicone elastomers market, holding a share of 40% in 2026. This can be attributed to growing automotive, electronics, healthcare, and construction industries in countries like China, India, Japan, and South Korea. Rising manufacturing activities and increasing demand for durable, heat-resistant, and flexible materials are also supporting the use of silicone elastomers across various applications.

In the U.S., demand for silicone elastomers is supported by medical devices, aerospace, electronics, automotive, and other high-value applications. CMI describes North America as a fast-growing region, with the U.S. benefiting from strong R&D activity, established manufacturing capabilities, and demand for high-performance silicone materials.

North America, spearheaded by the U.S., is poised to exhibit a CAGR of 8% during the forecast period. Medical-grade products are an important area because silicone is used in devices where flexibility, durability, and biocompatibility are needed.

Aerospace and specialized electronics also require materials that can perform under demanding conditions. Companies such as Dow Silicones Corporation and Momentive Performance Materials have a presence in the U.S. market, while suppliers and component manufacturers support custom applications. These conditions create demand for both standard silicone materials and specialized products designed around particular performance and regulatory needs.

7. Validate the Component Before Production

Selecting the material does not finish the qualification process. A prototype or sample can reveal issues that are difficult to identify from a material data sheet or drawing alone.

Depending on the part, engineers may need to check its dimensions, fit, compression, installation, hardness, surface condition, and function in the assembly.

Additional testing will depend on the aerospace program. Temperature exposure, aging, fluid compatibility, compression, or flammability testing may be required where specified.

The applicable drawing, specification, and customer requirements should determine what needs to be tested and how the finished component is accepted.

Key Considerations for Engineers and OEMs

A practical material decision starts with the component rather than one attractive property on a data sheet. The selected silicone needs to suit the operating temperature, surrounding environment, expected fluid exposure, required hardness, and sealing conditions.

The design must also make sense for the chosen manufacturing process. Dimensions and tolerances should be achievable, while inspection, traceability, testing as well as documentation requirements need to be established before production.

The growing silicone elastomers market also gives engineers more material and processing options. Newer silicone formulations, improved molding methods, additive manufacturing, and application-specific grades are expanding what manufacturers can produce. CMI notes that sustainability, digital manufacturing, and demand from EVs, healthcare, and electronics are likely to remain important areas of development.

Where there is uncertainty about fit or function, evaluating a prototype can provide useful information before larger quantities are released.

Custom Aerospace Silicone Rubber Components from Elastostar Rubber Corporation

Elastostar Rubber Corporation manufactures custom aerospace silicone seals, gaskets, O-rings, tubing, extruded profiles, and molded components in the USA.

The work can begin with an engineering drawing, CAD file, existing part, dimensions, or specific application requirements. Depending on the component, we support extrusion, molding, splicing and vulcanization, reverse engineering, prototyping, and production.

When requesting a quote, include as much practical information as possible: dimensions, tolerances, hardness, material specification, quantity, operating conditions, and any inspection or documentation requirements. This gives our team a clearer picture of what the finished component needs to do.

Frequently Asked Questions

What silicone rubber is best for aerospace applications?

There is no single grade that fits every aerospace application. Temperature, pressure, fluid exposure, hardness, compression, environmental conditions, and applicable specifications all influence the choice.

What properties matter most in aerospace silicone rubber?

The answer depends on the component. Temperature capability, compression set, flexibility, hardness, tear strength, environmental resistance as well as fluid compatibility are among the properties that may need review.

Which aerospace standards apply to silicone rubber?

That varies with the project. Requirements may come from A-A-59588, SAE/AMS specifications, ASTM test methods, OEM documents, engineering drawings, or customer specifications.

How should OEMs qualify a silicone rubber supplier?

Review the supplier's quality system along with its material knowledge, manufacturing processes, inspection capability, traceability, documentation, prototype support as well as ability to reproduce the part consistently.

Why is testing important before production?

Testing helps determine whether the finished part meets the requirements that matter in the actual application. Depending on the project, that can include dimensions, fit, material properties, environmental exposure, or functional performance.

Conclusion

Choosing silicone rubber for aerospace use is ultimately a component-specific decision. Temperature matters, but it has to be considered alongside the environment, fluids, compression, hardness, geometry, specifications, and manufacturing process.

The wider silicone elastomers market is moving toward more specialized materials as automotive, healthcare, electronics, transportation as well as other industries look for durable and flexible solutions. CMI estimates that the global market will grow from US$5.59 billion in 2026 to US$8.7 billion by 2033, with LSR, automotive applications, and high-performance silicone products playing important roles in this growth.

Defining these requirements early gives both the engineer and manufacturer a clearer basis for developing the part. It also makes prototype evaluation, inspection, testing as well as production requirements easier to establish.

Elastostar Rubber Corporation manufactures custom silicone rubber components in the USA for aerospace applications, including seals, gaskets, O-rings, tubing, extruded profiles, and molded parts.