BISCO®HT-6240 Transparent Solid Silicone Pads

SPECIFIC GRAVITY:
1.07 g/cc
DUROMETER, SHORE A [ASTM D2240]:
41
COMPRESSION SET, 70 HOURS @ 302˚F @ 25% [ASTM D395]:
<35%
TENSILE STRENGTH [ASTM D412]:
1040 psi
ELONGATION [ASTM D412]:
325%
TEAR RESISTANCE [ASTM D624]:
112 ppi
DIELECTRIC STRENGTH [ASTM D149]:
386 Volts/mil
DIELECTRIC CONSTANT [ASTM D150]:
2.76 kHz
DISSIPATION FACTOR [ASTM D495]:
0.003 kHz
DRY ARC RESISTANCE [ASTM D495]:
124 seconds
VOLUME RESISTIVITY [ASTM D257]:
10^14 Ohm-cm
THERMAL CONDUCTIVITY [ASTM D518]:
0.21 W/m˚K

Product Overview

BISCO® HT-6240 — Soft Solid Silicone — Technical Overview & FAQs

Product Overview

BISCO® HT-6240 is a soft, solid silicone rubber (40 Shore A) designed for low-compression sealing, gasketing, and vibration isolation. It delivers exceptional flexibility and resilience, maintaining reliable sealing performance over long service periods and extreme temperature ranges.

HT-6240 offers low compression set, excellent weather and UV resistance, and consistent mechanical strength, making it ideal for light-clamp assemblies and precision gaskets in aerospace, automotive, and electronic enclosures.

Applications

Environmental gaskets and seals for enclosures, doors, and access panels
Low-pressure sealing in HVAC, lighting, and electronic housings
Thermal and vibration isolation in industrial and transport systems
Die-cut gaskets, cushioning pads, and silicone washers

Key Properties

Shore A Hardness: 40 ± 5
Specific Gravity: 1.10 g/cc
Tensile Strength: ≥ 1000 psi
Elongation at Break: ≥ 700 %
Compression Set (70 h @ 302 °F): ≤ 25 %
Temperature Range: −80 °F to 450 °F (−62 °C to 232 °C)
Weather, Ozone, and UV Resistance: Excellent
Fluid Resistance: Moderate; resists oils, water, and coolants
Compliances: A-A-59588, AMS 3301–3305, FDA 21 CFR 177.2600, NSF 51

FAQs

What is BISCO HT-6240 used for?
BISCO HT-6240 is a soft, solid silicone material used for low-compression sealing, gasketing, and cushioning applications that require flexibility and environmental resistance.

What makes HT-6240 different from other solid silicones?
HT-6240 offers a softer durometer (40A), making it ideal for sealing delicate or irregular surfaces with low clamping force requirements.

What temperature range does HT-6240 handle?
It performs reliably from −80 °F to 450 °F (−62 °C to 232 °C), maintaining elasticity and sealing strength across wide temperature extremes.

Is HT-6240 suitable for outdoor exposure?
Yes — HT-6240 resists UV, ozone, and weathering, providing long-term durability in outdoor and high-humidity environments.

Can HT-6240 be supplied in adhesive-backed formats?
Yes — it is available as sheets, rolls, or precision die-cut gaskets with optional silicone or acrylic PSA for quick, peel-and-stick installation.

Contact H-O Products to request BISCO® HT-6240 samples, technical data sheets, or a custom gasket quote for your next design project - contact us.