Product Overview
40 Durometer Commercial Grade Solid Silicone — Technical Overview & FAQs
Product Overview
40 Durometer Commercial Grade Solid Silicone Rubber is a soft, flexible, and durable silicone elastomer designed for applications requiring moderate compressibility, high elasticity, and excellent sealing performance across wide temperature extremes.
At 40 Shore A, this grade provides a step up in firmness from 30A while still maintaining excellent flexibility. It is ideal for environmental seals, compression gaskets, and general-purpose silicone components where both softness and structural stability are required.
This material offers outstanding resistance to UV, ozone, weathering, and thermal cycling, ensuring long-term reliability in electronics, lighting, transportation, medical devices, and industrial systems.
Applications
Environmental and dust seals
Soft-to-medium compression gaskets
Lighting enclosure lens seals
Automotive and aerospace gasketing
Medical and laboratory equipment components
Pads, bumpers, insulation barriers, and die-cut gaskets
Key Properties
Durometer: 40 Shore A (soft, general-purpose firmness)
Tensile Strength: Moderate, suitable for sealing and gasketing
Elongation: High elasticity for flexible applications
Compression Set: Low, excellent long-term sealing stability
Temperature Range: –80 °F to +450 °F (–62 °C to +232 °C)
Environmental Resistance: Excellent UV, ozone, and weather resistance
Chemical Resistance: Good resistance to water, cleaning agents, and aging
Electrical: Good dielectric insulating properties
Available Formats: Sheets, rolls, strips, extruded profiles, die-cut gaskets, PSA-backed
Compliance: RoHS | REACH
FAQs
What is 40 Durometer Solid Silicone typically used for?
It is used for soft-to-medium compression gaskets, environmental seals, flexible components, and general-purpose industrial sealing in electronics, lighting, transportation, and appliance assemblies.
How firm is 40 durometer silicone?
40A silicone is soft but more supportive than 30A, providing:
Better dimensional stability
Improved sealing under moderate compression
Higher tear and mechanical strength than softer grades
Is 40 durometer silicone suitable for outdoor or harsh exposures?
Yes — silicone rubber is naturally resistant to UV, ozone, moisture, and weathering, making it ideal for long-term outdoor applications.
Does this silicone withstand high temperatures?
Yes — it performs well across extreme temperatures from –80 °F to +450 °F, maintaining flexibility and sealing integrity.
Can this material be die-cut or adhesive-backed?
Absolutely — H-O Products supplies die-cut gaskets, PSA-backed sheets, strips, and custom silicone components tailored to OEM specifications.
Contact H-O Products to request 40 Durometer Commercial Grade Solid Silicone samples, custom gasket fabrication, or engineering support for your silicone sealing applications - contact us.
