kSil™ KSV004 Medium
kSil™ KSV004 is a medium, lightweight closed-cell silicone sponge with a density of 24.3 lb/ft³ and a compression stress of 9.0 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: 9.0 psi (ASTM D1056)
- Tensile Strength: 64.3 psi (BSENISO 1798, ASTM D412)
- Elongation to Failure: 100% (BSENISO 1798, ASTM D412)
- Compression Set, 22 Hours @ 212°F, 50%: 3% (ASTM D1056)
- Density: 24.3 lb/ft³ (BSENISO 845, ASTM D3574)
- High Temperature Resistance: 446°F
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- Specifications
- Applications
- General Info
- FAQs
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 | 24.3 lb/ft³ | BSENISO 845, ASTM D3574 |
| Brittle Point | -80°C (-112°F) | ASTM D746 |
| Radiation Resistance | >10⁵ Grays (10⁷ Rads) typical | — |
Mechanical Properties
| Property | Value | Test Method |
| Compression Stress 25% Strain | 9.0 psi | ASTM D1056 |
| Compression Stress 40% Strain | 20.3 psi | BSENISO 3386 part 1,2 |
| Tensile Strength | 64.3 psi | BSENISO 1798, ASTM D412 |
| Elongation to Failure | 100% | 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 | 0.118 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 2D1 | Pass | — |
| FMVSS 302 | Pass | — |
| FAR 25 Appendix F Sec A 1 (i) & (ii) | Pass | — |
| CS 25 Appendix F Sec A 1 (i) & (ii) | Pass | — |
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 |
| 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 2D1 — 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)
- Flame resistant environmental sealing in rail, aerospace, automotive, marine, and military assemblies requiring IP67 sealing capability and the full kSil™ compliance suite at a medium stiffness level
- Interior and exterior seal gaskets in rail applications requiring EN45545-2 R22 and R23 HL3 compliance
- Aerospace sealing and gasketing components requiring FAR 25, CS 25, and Airbus ABD0031 compliance where medium compression resistance is needed to maintain seal geometry under higher flange loads
- Environmental sealing in electronics, HVAC, and lighting enclosures requiring low outgassing, low smoke, and low toxicity in a medium-grade sponge
- General flame resistant sealing across automotive and industrial markets where FMVSS 302, UL94 V0, and Bombardier SMP 800c compliance are required at 9.0 psi compression stress
Common industries: Rail, aerospace, automotive, marine, military, electronics, HVAC, lighting.
kSil™ KSV004 is a medium-grade closed-cell silicone sponge in the kSil™ V-0 series at 24.3 lb/ft³, positioned between KSV003 (19.4 lbs/ft³) and KSV005 (28.1 lb/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.
EN45545-2 classifications cover R22 and R23 at HL3 for interior and exterior seals in the 2 mm–25 mm thickness range.
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 64.3 psi — the highest among KSV001 through KSV004. Thermal conductivity is 0.118 W/m·K per DIN EN993-15. Brittle point is -80°C (-112°F) per ASTM D746. Radiation resistance is >10⁵ Grays (10⁷ Rads) typical.
The material is resistant to ozone, oxidation, UV, corona discharge, cosmic radiation, ionising radiation, and weather. No limiting oxygen index or smoke/toxicity test data is listed on this TDS.
Compliant with UL94 V0 (1.5 mm), EN45545-2 (HL3), NFPA 130, Bombardier SMP 800c, Airbus ABD0031, ASTM D1056 2D1, FMVSS 302, FAR 25 Appendix F Sec A 1 (i) & (ii), and CS 25 Appendix F Sec A 1 (i) & (ii).
What differentiates kSil™ KSV004 from other grades in the kSil™ V-0 series?
KSV004 is the medium grade in the kSil™ series at 24.3 lb/ft³ and 9.0 psi compression stress at 25% strain — firmer than KSV003 (19.4 lbs/ft³, 5.8 psi) and softer than KSV005 (28.1 lb/ft³, 14.5 psi). It has the highest tensile strength among KSV001–KSV004 at 64.3 psi, and the highest thermal conductivity among those grades at 0.118 W/m·K. EN45545-2 classifications are R22 and R23 at HL3. No limiting oxygen index or smoke/toxicity data is listed on this TDS.
Why is compression set critical for a medium flame resistant silicone sponge?
In medium-grade sponge sealing applications, the material is compressed under moderate flange loads and must maintain consistent contact force across thermal cycling and vibration over the service life of the assembly. A compression set above the design allowance means the seal has permanently deformed under the installed load, reducing contact force and potentially allowing ingress of fluids, gases, or contamination — and compromising the material's EN45545-2 and IP67 sealing performance. KSV004's compression set of 3% at 22 hours, 212°F, 50% per ASTM D1056 confirms reliable dimensional recovery under its rated service conditions.
What is the service temperature range for kSil™ KSV004?
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™ KSV004 suitable for regulated aerospace, automotive, and rail environments?
Yes. KSV004 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 2D1, and FMVSS 302, as listed on the TDS.
How should kSil™ KSV004 be specified?
Specify grade (KSV004), thickness (from the seven available gauges), color (Gray or Black), applicable compliance requirements, dimensional tolerances, and finished format (sheet, slit roll, or die-cut component).
