BISCO® HT-6240 Transparent
BISCO® HT-6240 is a transparent solid silicone rated at 41 Shore A, designed for demanding gasketing applications where material transparency improves application aesthetics or enables visual inspection. It delivers 1040 psi tensile strength, 112 ppi tear resistance, and a compression set of <35% (70 hours @ 302°F @ 25% deflection). The material is rated for service from -67°F to 392°F and provides resistance to UV, ozone, extreme temperatures, and most fluids.
Key Properties
- Durometer, Shore A: 41 — ASTM D2240
- Tensile Strength: 1040 psi — ASTM D412
- Elongation: 325% — ASTM D412
- Compression Set, 70 Hours @ 302°F @ 25%: <35% — ASTM D395
- Specific Gravity: 1.07 g/cc — —
Temperature Range: -67°F to 392°F
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Material / Substrate | Solid Silicone | — |
| Color | Transparent | — |
| Specific Gravity | 1.07 g/cc | — |
| Thickness | 0.010″, 0.020″, 0.031″, 0.063″, 0.125″ | — |
Mechanical Properties
| Property | Value | Test Method |
| Durometer, Shore A | 41 | ASTM D2240 |
| Tensile Strength | 1040 psi | ASTM D412 |
| Elongation | 325% | ASTM D412 |
| Tear Resistance | 112 ppi | ASTM D624 |
| Compression Set, 70 Hours @ 302°F @ 25% | <35% | ASTM D395 |
Thermal Properties
| Property | Value | Test Method |
| Temperature Range | -67°F to 392°F | — |
| Thermal Conductivity | 0.21 W/m·K | ASTM D518 |
Electrical Properties
| Property | Value | Test Method |
| Dielectric Strength | 386 Volts/mil | ASTM D149 |
| Dielectric Constant | 2.76 kHz | ASTM D150 |
| Dissipation Factor | 0.003 kHz | ASTM D495 |
| Dry Arc Resistance | 124 seconds | ASTM D495 |
| Volume Resistivity | 10^14 Ohm-cm | ASTM D257 |
Environmental Performance
| Property | Value | Test Method |
| Low Temperature Brittleness @ -80°F @ 3 Minutes | Pass | ASTM D2137 |
| UV Resistance | Yes | — |
| Ozone Resistance | Yes | — |
- Portable and handheld device gaskets where material transparency enhances aesthetics or enables visual verification
- Architectural lighting seals requiring a clear, weather-resistant gasket material
- Cell culture plate sealing where transparency supports visual inspection and contamination control
- Medical and industrial device gaskets providing enhanced sealing with transparent appearance
- Electronic and precision device sealing across a broad service temperature range
Common industries: Consumer electronics, architectural lighting, medical devices, industrial equipment, life sciences.
BISCO® HT-6240 is a transparent solid silicone at 41 Shore A, engineered for gasketing applications in portable devices, architectural lighting, cell culture plates, and medical and industrial assemblies where the visual appearance of the seal contributes to product aesthetics or where transparency enables verification of seal placement and alignment. High tear strength and extremely tight thickness tolerances support gasket integrity across a range of precision applications.
The material provides 386 Volts/mil dielectric strength, 10^14 Ohm-cm volume resistivity, 124 seconds dry arc resistance, and a thermal conductivity of 0.21 W/m·K. It passes low temperature brittleness testing at -80°F for 3 minutes per ASTM D2137 and demonstrates UV and ozone resistance.
What differentiates BISCO® HT-6240 from non-transparent solid silicone grades?
BISCO® HT-6240 is the only transparent grade in the BISCO® HT-6 series, providing 1040 psi tensile strength and 112 ppi tear resistance in a fully transparent form factor. Its transparency improves application aesthetics in visible sealing applications and enables visual verification of gasket placement and alignment in medical, laboratory, and lighting assemblies where colored or opaque grades are unsuitable.
Why is compression set an important consideration for solid silicone elastomers?
Compression set measures how well an elastomer recovers its original thickness after sustained compression. In sealing applications, a material with high compression set will permanently deform over time, reducing sealing force and allowing leak paths to develop. BISCO® HT-6240 achieves <35% compression set (70 hours @ 302°F @ 25% deflection per ASTM D395), supporting sustained sealing performance across its service temperature range.
What is the temperature range for BISCO® HT-6240?
BISCO® HT-6240 is rated for service from -67°F to 392°F, as listed on the TDS.
Is BISCO® HT-6240 suitable for electronic or medical sealing applications?
Yes. The TDS lists dielectric strength of 386 Volts/mil, volume resistivity of 10^14 Ohm-cm, dry arc resistance of 124 seconds, and UV and ozone resistance, supporting its use in electronic device and medical equipment sealing. No specific compliance standards are cited on the TDS.
How should BISCO® HT-6240 be specified?
Specify grade (BISCO® HT-6240), thickness, dimensional tolerances, and finished format.
