Soft Silicone Sponge Rubber Sheet | National Silicone

Soft Silicone Sponge

Closed Cell Silicone Sponge

This low compression set, soft silicone sponge is ideal for demanding sealing and gasket applications.

Roll - Silicone Stripping

It is produced with a fabric finish on both sides, is flexible and can handle extreme temperature environments. Our soft silicone sponge offers excellent compression set resistance and can maintain its resiliency under extended compression.

In Stock with Immediate Availability



  • Excellent for seals and gaskets
  • High compressibility
  • Low compression set
  • UV/Ozone resistant


  • ASTM D1056
  • ASTM D412
  • FAR 25.853


Available in – Continuous rolls or cut sheets
Thickness available (in) – 0.0625 to 0.500
Typical roll lengths (ft) – 25 to 100
Typical roll widths (in) – 36
Surface finishing – Fabric impression finish, both sides
Cell structure – Closed cell
Color – Red/orange, grey, black, white, *color matching available

*Subject to MOQ



-99°F to +450°F  (-73°C to 232°C)



Compression deflection (25%) psi (kPa) 3-8 (21-55) ASTM D1056
Density < 0.25” thick pcf (kg/m3) 43 (690) max. ASTM D1056
Density ≥ 0.25” thick pcf (kg/m3) 34 (550) max. ASTM D1056
Compression set (22h, 100°C) % 60 max. ASTM D1056
Tensile strength psi (kPa) 33 (225) min. ASTM D412

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More Information

ASTM D1056

  • ASTM D1056 Standard Specification for Flexible Cellular Materials—Sponge or Expanded Rubber
  • This material passes the ASTM D1056 specification for silicone materials.
  • This specification covers flexible cellular rubber products known as sponge rubber and expanded rubber, but does not apply to latex foam rubber or ebonite cellular rubber.
  • The base material for an open/closed cellular product may be made of synthetic, natural, or reclaimed rubber, or a mixture, and may contain other polymers or chemicals, or both, which may be modified by organic or inorganic additives.



  • ASTM D412 is a standard test methods for vulcanized rubber and thermoplastic elastomers—tension
  • This material passes the ASTM D412 specification for silicone materials.
  • ASTM D412 is the most common standard for determining the tensile properties of vulcanized (thermoset) rubber and thermoplastic elastomers. Compounds in this family are used to create a vast array of consumer goods such as tires, footballs, and rubber bands.


FAR 25.853

  • FAR 25.853 is a regulation part of the Federal Aviation Regulations (FARs), specifically addressing flammability requirements for materials used in the construction of commercial aircraft.
  • The regulation mandates that materials used inside the aircraft cabin, such as seat cushions, wall panels, and flooring, must be flame-resistant and able to withstand specific fire tests.
  • It includes specific criteria and test methods for assessing the flammability of these materials, ensuring that they do not easily ignite and, if they do, that they burn slowly and self-extinguish.
  • Compliance with FAR 25.853 is critical for aircraft certification, focusing on enhancing passenger safety by minimizing the risks associated with in-flight fires.




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We support our customers, and prospects throughout the purchase journey. Our team is made up of experienced professionals and highly trained engineers who will help with material selection, sampling, testing, and any application support you might need to accomplish your goals.




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