Introduction

For decades, Rogers’ HT-800 series silicone foams have been the benchmark for lightweight, durable gasketing materials. But what if you need a silicone sponge alternative with comparable compression, sealing, and thermal stability? Enter the RS-800 series: RS-800, RS-820, RS-840, and RS-870.

These materials are engineered to provide the same balance of softness, resilience, and temperature resistance—while offering cost-effectiveness and reliable supply outside of the Rogers catalog.


Product Lineup at a Glance

Grade Density / Firmness Relative Firmness Common Equivalent Standard Thicknesses
RS-800 Medium Density- Still Soft Medium Firmness HT-800 0.125″ to 0.500″ (0.8–12.7 mm)
RS-820 Medium-firm density Semi-firm HT-820 0.063” to .625”
RS-840 High density Extra-firm HT-840 0.125″ to 0.188″ (3.175–4.7752 mm)
RS-870 Low Density Extra-Soft HT-870 0.125″ to 0.250″ (3.175–6.35 mm)

All grades are supplied in sheets, rolls, and custom die-cut gaskets, making them true drop-in replacements for designs already built around HT-series materials.


Key Properties

  • Closed-cell silicone sponge structure → Excellent resistance to water, dust, and air leakage.

  • Wide operating temperature range (-55 °C to +200 °C typical) → Withstands extreme environments.

  • UV, ozone, and weather resistance → Long-term outdoor durability.

  • Low compression set → Maintains long-term gasketing performance.

  • Flame resistance → Meets many UL and ASTM requirements for flame and smoke safety.


Applications

The RS-800 series, like HT foams, is widely used in:

  • Electronics enclosures – environmental sealing and gap filling.

  • Aerospace & defense – lightweight gasketing with high durability.

  • Transportation (rail, EV, heavy equipment) – vibration damping, sealing against dust/water ingress.

  • Lighting enclosures & HVAC – weatherproof sealing and insulation.

  • General gasketing & cushioning – anywhere a reliable silicone sponge is needed.


Why Consider RS-800 Over HT-800?

  1. Direct equivalence – RS grades match HT grades in firmness and density.

  2. Performance parity – Both offer thermal stability, UV/weather resistance, and closed-cell sealing performance.

  3. Availability & cost – RS-series can be a more economical option without compromising function.

  4. Design flexibility – Always available as custom die-cut gaskets to fit exact design requirements.


Selecting the Right RS Grade

  • RS-800 (Medium): Ideal for delicate sealing where low closure force is critical.

  • RS-820 (Medium-firm): Good balance of compressibility and sealing strength.

  • RS-840 (Firm): For applications needing higher compression force and better mechanical support.

  • RS-870 (Soft): Best for super low closure pressure.


Conclusion

The RS-800 series (RS-800, RS-820, RS-840, RS-870) gives engineers a reliable, silicone sponge alternative to Rogers’ HT-800 family. With standard sheet thicknesses and the ability to supply precisely die-cut gaskets as the default, the RS-series delivers the same thermal, mechanical, and environmental benefits—often with added cost efficiency.

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