kSil™ KSV003 Soft-Medium
kSil™ KSV003 is a soft-medium, lightweight closed-cell silicone sponge with a density of 19.4 lbs/ft³ and a compression stress of 5.8 psi at 25% strain per ASTM D1056, available in seven thicknesses from 1/8″ to 1″. The material achieves UL94 V0 at 1.5 mm, passes EN45545-2 (HL3), NFPA 130, FAR 25 Appendix F Sec A 1 (i) & (ii), CS 25 Appendix F Sec A 1 (i) & (ii), Bombardier SMP 800c, and Airbus ABD0031, with a compression set of 3% at 22 hours, 212°F, 50% per ASTM D1056 and a service range of -76°F to 446°F continuous.
Key Properties
- Compression Stress 25% Strain: 5.8 psi (ASTM D1056)
- Tensile Strength: 44.1 psi (BSENISO 1798, ASTM D412)
- Elongation to Failure: 90% (BSENISO 1798, ASTM D412)
- Compression Set, 22 Hours @ 212°F, 50%: 3% (ASTM D1056)
- Density: 19.4 lbs/ft³ (BSENISO 845, ASTM D3574)
- High Temperature Resistance: 446°F
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- Specifications
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- General Info
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Physical Properties
| Property | Value | Test Method |
| Thickness | 1/8″, 3/16″, 1/4″, 3/8″, 1/2″, 3/4″, 1″ | — |
| Color | Gray (standard), Black | — |
| Cell Structure | Closed Cell | — |
| Material/Substrate | Silicone Sponge | — |
| Density | 19.4 lbs/ft³ | BSENISO 845, ASTM D3574 |
| Brittle Point | -80°C (-112°F) | ASTM D746 |
| Limiting Oxygen Index | 43.9% | ENO ISO 4589-2: OI |
| Radiation Resistance | >10⁵ Grays (10⁷ Rads) typical | — |
Mechanical Properties
| Property | Value | Test Method |
| Compression Stress 25% Strain | 5.8 psi | ASTM D1056 |
| Compression Stress 40% Strain | 13.1 psi | BSENISO 3386 part 1,2 |
| Tensile Strength | 44.1 psi | BSENISO 1798, ASTM D412 |
| Elongation to Failure | 90% | BSENISO 1798, ASTM D412 |
| Compression Set, 22 Hours @ 158°F, 50% | <1% | BSENISO 1856 |
| Compression Set, 22 Hours @ 212°F, 50% | 3% | ASTM D1056 |
| Water Absorption | <1% | ASTM D1056 |
Thermal Properties
| Property | Value | Test Method |
| Low Temperature Resistance | -76°F | — |
| High Temperature Resistance | 446°F | — |
| Intermittent Temperature Resistance | 482°F | — |
| Thermal Conductivity | 0.099 W/m·K | DIN EN993-15 |
Flame & Fire Performance
| Property | Value | Test Method |
| FAR 25 Appendix F Sec A 1 (i) & (ii) (Minimum) | 1.5 mm | FAR 25 APP. F SEC A 1 (i) |
| UL94 V0 | 1.5 mm | — |
| EN45545-2 (HL3) | Pass | — |
| NFPA 130 | Pass | — |
| Bombardier – SMP 800c | Pass | — |
| Airbus – ABD0031 | Pass | — |
| ASTM D1056 2D2 | Pass | — |
| FMVSS 302 | Pass | — |
| FAR 25 Appendix F Sec A 1 (i) & (ii) | Pass | — |
| CS 25 Appendix F Sec A 1 (i) & (ii) | Pass | — |
| Flame Spread (CFE) kWm², 2 mm | 26.57 | ISO 5658-2 |
| Flame Spread (CFE) kWm², 25 mm | 20.87 | ISO 5658-2 |
| Smoke Density (Ds MAX) 25 kWm², 3 mm | 18 | EN ISO 5659-2 |
| Smoke Density (Ds MAX) 25 kWm², 25 mm | 31 | EN ISO 5659-2 |
| Smoke/Toxicity 50 kWm⁻² Ds(4), 2 mm | 55 | EN ISO 5659-2 |
| Smoke/Toxicity 50 kWm⁻² Ds(4), 25 mm | 57 | EN ISO 5659-2 |
| V0F⁴ min, 2 mm | 159 | EN ISO 5659-2 |
| V0F⁴ min, 25 mm | 154 | EN ISO 5659-2 |
| CITᵍ, 2 mm | 0.03 | EN ISO 5659-2 |
| CITᵍ, 25 mm | 0.04 | EN ISO 5659-2 |
| Cone Calorimeter 50 kWm⁻² MARHE kWm², 2 mm | 76.67 | ISO 5660-1 |
| Cone Calorimeter 50 kWm⁻² MARHE kWm², 25 mm | 68.14 | ISO 5660-1 |
| Toxicity (CIT nlp) 600°C, 2 mm | 0.02 | NF X 70-100-1 & 2 |
| Toxicity (CIT nlp) 600°C, 25 mm | 0.05 | NF X 70-100-1 & 2 |
Environmental Performance
| Property | Value | Test Method |
| Ozone Resistant | Yes | — |
| Oxidation Resistant | Yes | — |
| UV Resistant | Yes | — |
| Corona Discharge Resistant | Yes | — |
| Cosmic Radiation Resistant | Yes | — |
| Ionising Radiation Resistant | Yes | — |
| Weather Resistant | Yes | — |
EN45545-2 Classifications
| Property | Description | Rating |
| R1 | Interior surfaces (& non-listed interior products <0.2m²) (2 mm – 25 mm thickness range) | HL2 |
| R2 | Limited surfaces (2 mm – 25 mm thickness range) | HL3 |
| R3 | Strips (2 mm – 25 mm thickness range) | HL3 |
| R7 | Gangway surfaces, ducting (& non-listed exterior products <0.2m²) (2 mm – 25 mm thickness range) | HL2 |
| R8 | Roof (external) (2 mm – 25 mm thickness range) | HL2 |
| R17 | Cab housing (2 mm – 25 mm thickness range) | HL2 |
| R22 | Interior seals (& non-listed interior products <0.2m²) (2 mm – 25 mm thickness range) | HL3 |
| R23 | Exterior Seals (& non-listed exterior products <0.2m²) (2 mm – 25 mm thickness range) | HL3 |
Compliance
- UL94 V0 — Compliant (1.5 mm)
- EN45545-2 (HL3) — Compliant (Pass)
- NFPA 130 — Compliant (Pass)
- Bombardier SMP 800c — Compliant (Pass)
- Airbus ABD0031 — Compliant (Pass)
- ASTM D1056 2D2 — Compliant (Pass)
- FMVSS 302 — Compliant (Pass)
- FAR 25 Appendix F Sec A 1 (i) & (ii) — Compliant (Pass)
- CS 25 Appendix F Sec A 1 (i) & (ii) — Compliant (Pass)
- Rail applications requiring the broadest EN45545-2 classification coverage in the kSil™ series, including interior surfaces (R1), limited surfaces (R2), strips (R3), gangway/ducting (R7), roof (R8), cab housing (R17), and interior/exterior seals (R22, R23)
- Interior and exterior sealing in aerospace applications requiring FAR 25, CS 25, and Airbus ABD0031 compliance in a soft-medium grade with detailed flame, smoke, and toxicity test data
- Flame resistant environmental sealing in automotive, marine, and military assemblies where FMVSS 302 and UL94 V0 compliance are required at a soft-medium stiffness level
- Gasketing and strip applications in rolling stock and rail vehicles requiring R2, R3, and R7 EN45545-2 HL3 and HL2 classifications
- Low-outgassing sealing components in electronics, HVAC, and lighting enclosures requiring documented smoke density and toxicity data per ISO 5659-2 and NF X 70-100
Common industries: Rail, aerospace, automotive, marine, military, electronics, HVAC, lighting.
kSil™ KSV003 is a soft-medium-grade closed-cell silicone sponge in the kSil™ V-0 series at 19.4 lbs/ft³, positioned between KSV002 (13.7 lbs/ft³) and KSV004 (24.3 lbs/ft³). The smooth-skin construction provides sealing capability to IP67. Available in seven thicknesses from 1/8″ to 1″, it is suited to environmental sealing, gasketing, and cushioning in rail, aerospace, automotive, marine, military, electronics, HVAC, and lighting applications.
KSV003 carries the broadest EN45545-2 classification coverage in the kSil™ series, achieving HL3 ratings across R1, R2, R3, R7, R8, R17, R22, and R23.
The material achieves a compression set of 3% at 22 hours, 212°F, 50% per ASTM D1056, and <1% at 158°F per BSENISO 1856. Tensile strength is 44.1 psi. Thermal conductivity is 0.099 W/m·K per DIN EN993-15. Brittle point is -80°C (-112°F) per ASTM D746. Limiting oxygen index is 43.9% per ENO ISO 4589-2 — the highest in the kSil™ series. Radiation resistance is >10⁵ Grays (10⁷ Rads) typical. Flame spread (CFE) is 2 mm = 26.57 kWm² and 25 mm = 20.87 kWm² per ISO 5658-2.
Smoke density (Ds max) at 25 kWm² is 3 mm = 18 and 25 mm = 31 per EN ISO 5659-2. Smoke/toxicity at 50 kWm⁻² Ds(4) is 2 mm = 55 and 25 mm = 57. V0F⁴ min: 2 mm = 159, 25 mm = 154. CITᵍ: 2 mm = 0.03, 25 mm = 0.04. Cone calorimeter MARHE at 50 kWm⁻²: 2 mm = 76.67 kWm², 25 mm = 68.14 kWm² per ISO 5660-1. Toxicity (CIT nlp) at 600°C: 2 mm = 0.02, 25 mm = 0.05 per NF X 70-100-1 & 2. The material is resistant to ozone, oxidation, UV, corona discharge, cosmic radiation, ionising radiation, and weather.
Compliant with UL94 V0 (1.5 mm), EN45545-2 (HL3), NFPA 130, Bombardier SMP 800c, Airbus ABD0031, ASTM D1056 2D2, FMVSS 302, FAR 25 Appendix F Sec A 1 (i) & (ii), and CS 25 Appendix F Sec A 1 (i) & (ii).
What differentiates kSil™ KSV003 from other grades in the kSil™ V-0 series?
KSV003 carries the broadest EN45545-2 classification coverage in the kSil™ series — eight R-classifications (R1, R2, R3, R7, R8, R17, R22, R23) versus two (R22, R23) for KSV002, KSV004, and KSV005, and four (R10, R21, R22, R23) for KSV001. It also has the highest limiting oxygen index in the series at 43.9%, and it is the only grade to list ASTM D1056 2D2 (versus 2D1 for other grades). The most extensive smoke, toxicity, and flame spread test data in the series is documented on this TDS.
Why is compression set critical for a soft-medium flame resistant silicone sponge?
In flame resistant sealing and strip applications across rail vehicles, the sponge must maintain consistent contact force against mating surfaces through the entire service interval — including sustained thermal, mechanical, and vibration loading. A compression set above the design allowance means the seal has permanently deformed and may no longer maintain IP67 or the required flame and smoke barrier performance required by EN45545-2 classifications. KSV003's compression set of 3% at 22 hours, 212°F, 50% per ASTM D1056 confirms reliable dimensional recovery across its rated service conditions.
What is the service temperature range for kSil™ KSV003?
Low temperature resistance is -76°F, high temperature resistance is 446°F, and intermittent temperature resistance is 482°F, as listed on the TDS.
Is kSil™ KSV003 suitable for regulated aerospace, automotive, and rail environments?
Yes. KSV003 passes UL94 V0 (1.5 mm), EN45545-2 (HL3), NFPA 130, FAR 25 Appendix F Sec A 1 (i) & (ii), CS 25 Appendix F Sec A 1 (i) & (ii), Bombardier SMP 800c, Airbus ABD0031, ASTM D1056 2D2, and FMVSS 302, as listed on the TDS.
How should kSil™ KSV003 be specified?
Specify grade (KSV003), thickness (from the seven available gauges), color (Gray or Black), applicable compliance requirements, EN45545-2 R-classification requirements, dimensional tolerances, and finished format (sheet, slit roll, or die-cut component).
