Compression Set (ASTM D395)
Compression Set (ASTM D395)
Compression Set Testing (ASTM D395)
Precision compression set testing services to evaluate the long-term sealing performance and resilience of elastomer materials under constant deflection.
Test Overview
Compression set measures the ability of rubber compounds to return to their original thickness after prolonged compression at elevated temperatures. This critical property indicates how well a seal will maintain contact pressure over its service life.
Test Methods
- Method A – Constant force compression
- Method B – Constant deflection (most common for O-rings and seals)
Standard Conditions
- Temperature range: 23°C to 200°C (73°F to 392°F)
- Compression duration: 22 hours or 72 hours (per specification)
- Deflection: Typically 25% of original thickness
Applications
Essential for qualifying materials for automotive seals, hydraulic O-rings, gaskets, and any application where long-term compression resistance is critical to performance.
Deliverables
Detailed test report including compression set percentage, test conditions, specimen dimensions, and material identification. Results provided within 5-7 business days of sample receipt.

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