ISO 815-2:2019 is an ISO test method for determining compression set of vulcanized and thermoplastic rubber at low temperatures. It is used to quantify how well an elastomer recovers thickness after being held under a defined compressive strain while cold, which is especially important where sealing force and resilience must be retained in cold service.
The standard includes two alternative approaches, including an instrumented option that measures thickness during recovery at the test temperature. If you need help aligning your product requirement to the right method and conditioning approach, contact our team to discuss your application and test temperature range.
ISO 815-2:2019 — Rubber, vulcanized or thermoplastic — Determination of compression set — Part 2: At low temperatures
ISO 815-2 focuses on compression set behavior measured at low temperature, where elastomers can be affected by phenomena such as glass hardening or crystallization. Because these effects are temperature-dependent and reversible, measurements are taken at the test temperature.
This document is typically referenced when qualifying rubber compounds or finished elastomer components for cold environments, or when comparing candidate materials for low-temperature sealing performance.
Quick Definition
Document type: Test method.
What it measures: Compression set characteristics (permanent set / loss of recovery after compression) at low temperature for vulcanized and thermoplastic rubbers.
Method options: Two methods are defined; one is based on the approach used in ISO 815-1, and one uses a specified device to measure and record test piece thickness during recovery (results between the two methods are not intended to correlate).
What This Standard Covers
ISO 815-2 provides procedures to determine how a rubber test piece behaves after prolonged compression at a specified low temperature, with the recovery measurement performed at that same test temperature.
It is commonly used to support material selection, compound verification, and comparative benchmarking where cold-temperature resilience is a functional requirement.
Why This Standard Matters in Testing
Compression set is a practical durability indicator for elastomers used under continuous squeeze. At low temperatures, a material that performs well at room temperature may not recover adequately, which can reduce sealing load and increase leakage risk or functional drift.
Because ISO 815-2 measurements are taken at the test temperature, it helps teams evaluate cold-performance behavior without warming effects masking the result.
Common Materials, Product Types, or Applications Covered
ISO 815-2 is most often applied to elastomer materials and components that must maintain elasticity while cold.
- Vulcanized rubber and thermoplastic rubber materials used in sealing and cushioning functions
- Seals, gaskets, O-rings, boots, and similar elastomer parts (where compression recovery supports function)
- Industrial and transportation components exposed to cold climates, refrigerated service, or cold-start conditions
Common Test or Verification Workflow
Most ISO 815-2 workflows follow a controlled sequence of compression, cold exposure, and recovery measurement.
- Prepare and measure the test piece thickness.
- Compress the test piece to a specified strain in a compression set fixture.
- Condition/hold the compressed test piece at the specified low temperature for the required duration.
- Release compression and measure recovery at the test temperature (method-dependent).
- Calculate and report compression set per the selected method, alongside the test conditions used.
Workflow note: Method selection matters because method 2 applies a defined recovery measurement approach using a specified device, and results are not intended to correlate directly with method 1.
Equipment Commonly Used for This Standard
ISO 815-2 is equipment-oriented around controlled compression, stable low-temperature exposure, and accurate thickness measurement during recovery.
- Compression set fixture (jig): Compression plates and spacers (or equivalent strain-control hardware) suitable for low-temperature use.
- Low-temperature chamber/cabinet: Capable of maintaining the fixture and test pieces at the specified test temperature.
- Thickness measurement: A suitable thickness gauge or measurement system appropriate for the method and required resolution at low temperature.
- Method 2 device (where applicable): A specified measurement device that can measure and record test piece thickness during recovery.
Practical caution for equipment selection: Low-temperature compression set is sensitive to how temperature is maintained and how recovery thickness is measured at temperature. Quoting the right setup typically requires knowing the target temperature range, specimen geometry constraints, and which method (1 or 2) your customer or specification calls out.
If you are selecting fixtures and a cold chamber package for ISO 815-2 work, you can request a detailed quote for an equipment configuration matched to your temperature range and throughput.
How to Read This Designation or Revision
ISO 815-2 identifies Part 2 of ISO 815, covering compression set determination at low temperatures.
Year matters: The edition year (for example, ISO 815-2:2019) should be included in purchase specs, test reports, and procurement documents to avoid method and reporting mismatches.
Status context: ISO 815-2:2019 is published as an International Standard and has been confirmed as current by ISO’s systematic review process.
Related Standards, Methods, or Frameworks
ISO 815-2 is part of the ISO 815 compression set series and is commonly paired with ambient/elevated temperature compression set evaluation when qualification spans multiple service temperatures.
- ISO 815-1: Determination of compression set at ambient or elevated temperatures (methodology referenced by ISO 815-2 method 1).
Get help quoting ISO 815-2 test equipment
For low-temperature compression set work, the right configuration depends on your required temperature range, method choice, and how you need to measure recovery at temperature. Share your target conditions and specimen details and ask for a quote on a chamber + fixture + measurement package aligned to ISO 815-2 testing.