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Izod and Charpy impact testing uses a pendulum to strike a plastic, composite, or other polymeric test specimen following the specific test conditions set forth in standard methods.


The Izod impact test method and Charpy impact test method utilize a pendulum system to apply a force to a V-notched or to an un-notched sample. The Izod impact test determines the strength, brittleness, toughness, and notch sensitivity of plastic, composite, and other polymer materials. Our scientists can assist you with determining the appropriate type of specimen and test configuration to meet your testing needs, and test parameters.

Impact energy values are useful for quality control and specifications purposes.  Other purposes include:

Product comparison
Determination of mechanical property degradation as a result of product use, accelerated aging, or chemical exposure
Comparison of passed and failed batches of a single product.

Izod and Charpy impact tests are performed in accordance with standard methods, such as:

  • ASTM D4812
  • ASTM D256
  • ASTM D6110
  • ISO 179
  • ISO 180

Sample Considerations

Izod impact test specimens may be notched or unnotched.  The standard notched specimen produces a stress concentration that increases the probability of a brittle fracture rather than a ductile fracture.  The unnotched specimen is usually used with reinforced plastic materials.  However, unnotched specimens can be used to evaluate other filled or unreinforced materials where a stress-concentrating notch is not desired.

The Charpy impact test, utilizing a notched specimen, is similar to the Izod impact tests when performed on notched test specimens.

Contact us to determine your specific impact testing needs and associated sample considerations.


SGS PSI has a dedicated laboratory for physical testing of polymers, plastic, and rubber materials.  Over the years we have provided our clients with reliable data sets for mission critical decision making.  We have used Izod impact and Charpy impact tests as part of material qualification programs, comparisons of materials for second source procurement, and to aid in the root cause analysis during material failure investigations.

The Izod impact test and Charpy impact test are applicable to a wide range of plastic, composite, and other polymeric materials, including:

  • Rigid molded thermoplastics
  • Rigid extruded thermoplastics
  • Filled polymer compounds
  • Reinforced plastic compounds
  • Rigid thermosetting sheets
  • Composites
  • Laminates
  • Thermotropic liquid crystal polymers