High Strength Silicone Sheeting & Uncured Compounds

High Strength Silicone That Meets A-A-59588 3B

High-strength silicone sheets from ElastaPro are engineered for demanding applications that require significantly higher tensile strength, tear resistance, and compression-set performance than general-purpose grades.

Formulated with ingredients compliant with FDA 21 CFR 177.2600 for food contact, these premium-grade materials meet A-A-59588 Class 3B military standards and provide continuous thermal stability from −80°F to +450°F (−62°C to +232°C).

Every batch is Made in USA under our ISO 9001:2015 / AS9100D quality system and shipped with a complete Certificate of Analysis (COA).

Need High Strength Silicone Sheet or Slit Rolls?

We supply continuous rolls, pre-cut sheets, and uncured compounds with low minimums and fast lead times.

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Products and Key Technical Specifications

ElastaPro offers high strength silicone sheeting in a range of durometers.

ProductDurometer (Shore A)Tensile Strength (PSI)Tear Resistance (PPI)
ESS30HS30 ± 51200170
ESS40HS40 ± 51250180
ESS50HS50 ± 51300200
ESS60HS60 ± 51350210
ESS70HS70 ± 51300190
ESS80HS80 ± 51250170

Standard Sheet Sizes and Roll Dimensions

This solid silicone sheeting is available in various sizes, including some of the widest widths in the industry. 

MeasurementTypeImperialMetric
WidthStandard36" 914 mm
WidthStandard48" 1219 mm
WidthCustomUp to 67"Up to 1701.8 mm
ThicknessRange0.020" to 0.375"0.508 mm to 9.525 mm
Cut SheetStandard12″ × 12"30.48 cm x 30.48 cm
Cut SheetStandard24″ × 24″60.96 cm x 60.96 cm
Cut SheetStandard36″ × 36″91.44 cm x 91.44 cm
Cut SheetStandard48" x 48"121.92 cm x 121.92 cm
Cut SheetCustom
Linear LengthContinuousUp to 300" ftUp to 91.44 m

High Strength vs. General Purpose Silicone

Compare this material to general purpose silicone during product selection.

  • Tear Propagation: General-purpose silicone can tear easily once notched under stress. High-strength formulations (incorporating treated fumed silica reinforcement) resist nick propagation and withstand rapid dynamic flexing.

  • Flex Fatigue Resistance: Ideal for diaphragms, bellows, and dynamic seals that undergo millions of actuation cycles without physical degradation.

  • Tensile Thresholds: Delivers 1,200 to 1,350+ PSI tensile strength compared to standard commercial grades (typically 600–800 PSI).

High‑Strength Silicone FAQs

What is high-strength silicone, and how does it differ from standard silicone rubber?

High-strength silicone is an advanced, high-consistency rubber (HCR) or liquid silicone rubber (LSR) formulation engineered for superior mechanical durability.

By incorporating treated fumed silica reinforcement (20–40 phr) and optimized platinum or peroxide crosslinking, high-strength silicones achieve tensile strengths between 10–14 MPa (compared to 4–7 MPa for general-purpose grades) and tear strengths between 30–55 kN/m, effectively doubling the tear resistance of standard silicone.

High-strength silicone is engineered to withstand extreme physical stress, cut propagation, and dynamic deformation. Key mechanical performance benchmarks include:

  • Tensile Strength (ASTM D412): 10–14 MPa

  • Tear Strength (ASTM D624): 30–55 kN/m

  • Elongation at Break: 400% to 700%

  • Hardness Range: Available from 30 to 80 Shore A

  • Compression Set (ASTM D395): Below 20% after 22 hours at 175°C (347°F)

Driven by the flexible siloxane backbone (–Si–O–Si–), high-strength silicone maintains mechanical resilience across a broad temperature range from −60°C to +230°C (−76°F to +446°F) continuous, with short-term thermal excursions up to 250°C–300°C.

It also features an ultra-low glass transition temperature ($T_g \approx -127^\circ\text{C}$), ensuring the material remains flexible in frigid conditions without cracking.

High-strength silicone exhibits high chemical inertness and environmental stability against:

  • UV, Ozone, and Weathering: Complete resistance to atmospheric degradation and solar oxidation.

  • Aqueous Solutions & Fluids: Excellent resistance to water, neutral pH solutions, brake fluids, coolants, and transmission fluids.

  • Mild Acids & Bases: Maintains integrity against low-concentration chemicals.

  • Note on Hydrocarbons: Silicone swells when exposed to non-polar hydrocarbons (gasoline, toluene, xylene). For continuous fuel immersion, fluorosilicone (FVMQ) is recommended.

High-strength silicone retains exceptional dielectric properties across fluctuating temperatures and frequencies, making it ideal for electrical enclosures and aerospace connectors:

  • Dielectric Strength: ~20–25 kV/mm

  • Dielectric Constant ($\varepsilon_r$): ~2.7–3.2 at 1 MHz

  • Dissipation Factor ($\tan \delta$): <0.003 at 1 MHz

Because of its unique combination of high tear resistance, thermal endurance, and low compression set, high-strength silicone is specified for high-stress applications, including:

  • Aerospace & Defense: Vibration dampers, high-tear door/hatch seals, O-rings, and connector gaskets.

  • Automotive: Turbocharger hoses, engine compartment gaskets, and structural isolators under high thermal cycling.

  • Medical Devices: Precision medical tubing, catheters, and biocompatible seals (ISO 10993 compliant).

  • Electronics & Energy: High-voltage insulation, outdoor power distribution seals, and encapsulants.

High-strength silicone is processed using High Consistency Rubber (HCR) for calendar-cured solid sheeting, extruded profiles, and compression-molded parts, or Liquid Silicone Rubber (LSR) for rapid two-part injection molding. Post-curing is frequently performed to remove volatile byproducts, stabilize crosslinking, and achieve optimal mechanical properties.

  • ASTM D412 (Tensile Properties) & ASTM D624 (Tear Strength)

  • ASTM D395 (Compression Set) & ASTM D471 (Fluid Resistance)

  • A-A-59588 Class 3B (Military Specification for High Tear Strength Silicone)

  • FDA 21 CFR 177.2600 (Rubber Articles Intended for Repeated Food Contact)

  • UL 94 (Flammability Ratings) & ISO 10993 (Biocompatibility)