DIN ISO 815-1 specifies laboratory methods for determining compression set of vulcanized rubber and thermoplastic rubber at ambient or elevated temperatures. Compression set is a key indicator of how well an elastomer recovers after being held under a fixed compressive strain for a defined time and temperature.
This standard is commonly used when qualifying rubber compounds and finished parts such as seals, gaskets, and O-rings for long-term static loading, especially where heat exposure can drive permanent deformation. If you are unsure which method option or temperature condition fits your requirement, talk with our team about aligning the setup to the edition cited in your customer specification.
DIN ISO 815-1: Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At ambient or elevated temperatures
DIN ISO 815-1 is a test-method standard for measuring compression set (permanent thickness loss / residual deformation) after prolonged compression at constant strain. It provides one method at ambient temperature and multiple method options at elevated temperature, which differ in how the test piece is handled at the end of the compression period.
| Item | What DIN ISO 815-1 Covers |
|---|---|
| Material scope | Vulcanized rubber and thermoplastic rubber |
| Property measured | Compression set after prolonged compression at constant strain |
| Temperature conditions | Ambient (one method) and elevated temperature (multiple method options) |
| Typical strain logic | Normally 25% strain; lower strain levels are used for higher-hardness rubbers |
| Hardness range referenced | Intended for rubbers within about 10 IRHD to 95 IRHD |
Quick Definition
DIN ISO 815-1 is used to quantify how much an elastomer stays “set” (does not fully recover thickness) after being compressed at a specified strain for a specified time at ambient or elevated temperature.
What This Standard Covers
DIN ISO 815-1 defines a controlled approach to compressing rubber test pieces to a fixed strain, conditioning them at a defined temperature for a defined duration, then measuring recovery and calculating compression set. It is written for vulcanized elastomers and thermoplastic rubbers where retaining elastic recovery after compression is important.
At elevated temperatures, the standard includes multiple method options (commonly referenced as different method letters) based on how the test piece is released and allowed to recover at the end of the conditioning period. That end-of-test handling can significantly affect results, so method selection should match the requirement being flowed down by the customer specification.
Why This Standard Matters in Testing
Compression set is often used as a screening and qualification metric for parts that must maintain sealing force or dimensional resilience under long-term static compression. Elevated-temperature compression set is especially relevant when elastomers are exposed to heat aging mechanisms that reduce recovery and increase permanent deformation.
In procurement and QA/QC workflows, DIN ISO 815-1 is frequently used to compare compounds, verify batch-to-batch consistency, and confirm that finished rubber parts meet an application-specific limit after the required time/temperature exposure.
Common Materials, Product Types, or Applications Covered
This standard is broadly applicable across elastomer families and is commonly specified for components that operate under compressive preload.
Common products: O-rings, molded seals, gaskets, washers, bushings, bumpers, vibration isolation pads, and other rubber elements designed to carry static compression.
Common use environments: Under-hood automotive sealing, industrial fluid handling, HVAC sealing elements, appliance seals, and general-purpose engineering rubber goods where heat exposure and long dwell times are expected.
Common Test or Verification Workflow
Compression set testing under DIN ISO 815-1 is typically run as a controlled conditioning-and-measurement sequence rather than a continuous-load mechanical test.
Typical workflow elements: (1) prepare standard test pieces or representative cut specimens, (2) measure initial thickness, (3) install in a compression device set to the specified strain, (4) condition at the required ambient or elevated temperature for the specified time, (5) release per the selected method option, (6) allow recovery per the standard, then (7) measure final thickness and calculate compression set.
Practical sensitivity: Oven uniformity, fixture parallelism, spacer accuracy, and the specified recovery condition can all change results. For consistent comparisons, keep the cited method option, temperature, duration, and measurement approach aligned across all lots and labs.
Equipment Commonly Used for This Standard
DIN ISO 815-1 typically drives selection of fixtures and temperature-conditioning equipment more than it drives selection of a universal testing machine.
Common equipment: Compression set fixtures (plates, spacers, and tightening hardware), thickness measurement tools (bench thickness gauge or suitable micrometer), and a temperature-controlled oven or chamber for the specified exposure condition.
Configuration considerations: Fixture capacity (number of specimens), spacer sets for the specified strain levels, corrosion-resistant hardware for long elevated-temperature exposures, and sufficient oven volume and airflow to maintain stable temperature with loaded fixtures.
If you are comparing fixture formats, oven sizes, or multi-specimen throughput, you can request a detailed quote for a compression set setup matched to your specimen geometry and temperature range.
How to Read This Designation or Revision
DIN ISO 815-1 indicates the German adoption (DIN) of ISO 815-1. “Part 1” covers ambient and elevated temperature methods; low-temperature compression set is addressed in a separate Part 2.
In many purchasing documents, the citation includes an edition year and/or a DIN publication date. Because method options and procedural details can change between editions, equipment setup, conditioning parameters, and reporting should be matched to the exact edition stated on the drawing, control plan, or customer specification.
Related Standards, Methods, or Frameworks
Compression set requirements are often paired with other elastomer verification tests depending on the service environment and failure modes being controlled.
Commonly paired references: ISO 815-2 (compression set at low temperatures) when cold-service sealing performance is critical.
Get help selecting a compression set test setup
If you need to match fixtures, spacer sets, and oven/chamber capability to the specific DIN ISO 815-1 edition and method option cited in your requirement, contact our team to discuss your temperature range, specimen format, and throughput targets.