HT-800 | NS-120 | Medium Silicone Foam | National Silicone

NS-120 Medium Silicone Foam (HT-800 Foam Replacement)

Cellular Silicone Foam

NS-120 is the ideal choice for applications ranging from vibration management to gap filling to gasket and sealing. It is a direct comparable to Rogers Bisco® HT 800 foam material.

HT-800 vs NS-120 Medium-Firm Silicone Foam Comparison Chart
This medium-firm silicone foam is cast from liquid silicone with smooth skin and closed cells giving it a very unique and adaptable set of proprieties. From shock reduction to vibration isolation to enhanced sealing capabilities, this performance foam offers UL 94 V-0 flame resistance, FDA compliance for repeated use in contact with food and has excellent aging proprieties.

In Stock with Immediate Availability





Available in – Continuous rolls or cut sheets
Thickness available (in) – 0.032 to 0.500
Roll lengths available (ft) – *19 to 65.6, depending on thickness
Typical roll widths (in) – *19 & 36 (for 0.031 to 0.125)
Typical roll widths (in) – *19 (for 0.188″ and above)
Surface finishing – Smooth finish, both sides
Cell structure – Closed cell
Color – Grey, Black, *White, *Red
*Subject to MOQ

* Download roll size guide


-67°F to +392°F  (-55°C to 200°C)



Compression deflection (25%) psi (kPa) 6-14 (41-96) ASTM D1056
Density pcf (kg/m3) 23 (370) ASTM D1056
Compression set (22h, 100°C) % < 1 ASTM D1056
Tensile strength psi (kPa) 32 (220) ASTM D412
Flammability V-0 rating UL 94

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National Silicone 88-NS120-Medium-Foam_202304
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UL 94 V-0

  • UL 94 V-0 is a safety and flammability standard by Underwriters Laboratories.
  • This material is compliant with the UL 94 V-0 test standard for flammability.
  • The vertical burn test measures the self-extinguishing time of a vertically oriented polymer specimen. The test evaluates both the burning and afterglow times and dripping of the burning test specimen.
  • In order to be rated UL 94 V-0, the burning must stop within 10 seconds, no flame propagation or dripping.


UL 50E

  • UL 50E is an enclosures for electrical equipment standard by Underwriters Laboratories.
  • This material is compliant with the standard intended to be installed and used in non-hazardous indoor/outdoor locations.
  • This standard also covers additional environmental construction and performance requirements for enclosures.


UL 157 

  • UL 157 is a standard for nonmetallic gasket and seal materials by Underwriters Laboratories.
  • The general use of these gasket and seal materials is to exclude or hold within an enclosure materials that are liquid, gas, or vapor.
  • materials covered in this standard include elastomers, composite gasket material, flexible cellular material, thermoplastics and thermoplastic elastomers for specific end products.


UL 508 

  • UL 508 is industrial control equipment standard by Underwriters Laboratories.
  • The standard covers industrial control devices, and devices accessory thereto, for starting, stopping, regulating, controlling, or protecting electric motors.
  • In addition these requirements also cover industrial control devices or systems that store or process information and are provided with an output motor control function(s).


21 CFR 177.2600

  • 21 CFR 177.2600 is a specification from the U.S. Code of Federal Regulations (CFR) used by the Food and Drug Administration (FDA).
  • This material is compliant with the requirements of 21 CFR 177.2600.
  • The specification covers rubber articles intended for repeated use and may be safely used in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food, subject to the provisions of this section.
  • Meaning this material is generally recognized as safe, and can be used in applications where repeated use in contact with food occurs.


ASTM D1056 2D2

  • ASTM D1056 is a specification for flexible cellular materials (sponge or expanded rubber) from the American Society for Testing and Materials.
  • This material fully passes the ASTM D1056 2D2 specification for flexible cellular materials.
  • The 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.
  • Type 2 – Closed-cell rubber.
  • Class D – Cellular rubber made from synthetic rubber can meet extreme temperature resistance −103 to 347°F (−75 to 175°C).
  • Grade 2 – For Types 1 and 2 cellular rubber, has a compression deflection range from 5 to 9 psi (34.5 to 62.1 kPa).



  • AMS3195 is an aerospace material specification from SAE International Group.
  • The specification covers silicone rubber sponge in the form of sheet, strip, extrusions, and molded shapes.
  • Our medium density silicone sponge sheet is in accordance with the physical property requirements of AMS3195 test standard.
  • This product has been used typically for general applications requiring closed-cell, medium sponge rubber that will be flexible from -103 to +401 °F (-75 to +205 °C), but usage is not limited to such applications. Compression set may be high at the higher temperature.


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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