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.