Charpy Impact Test
Charpy testing answers a question tensile testing cannot: will this material absorb a sudden blow, or shatter?
The Charpy impact test measures a material's toughness by striking a notched specimen with a swinging pendulum and recording the energy absorbed in fracturing it, reported in joules.
- Measures
- Energy absorbed in fracture, joules
- Specimen
- Notched, standard dimensions
- Temperature
- Specified to match service
- Reporting
- Average of three plus individual minimum
Charpy Impact Test at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Measures: Energy absorbed in fracture, joules
- Specimen: Notched, standard dimensions
- Temperature: Specified to match service
- Reporting: Average of three plus individual minimum
Why Temperature Is Specified
Steel toughness falls sharply below its transition temperature, changing from ductile to brittle behaviour. A material tough at 20°C may shatter at minus 20°C, so the test temperature must match the service condition or the result means nothing.
Interpreting Results
Results are reported as absorbed energy in joules, usually as an average of three specimens with a minimum for any individual one. Specifications state both, because a single low result reveals inconsistency that an average would hide.
Topics covered on this page
- Charpy impact test
- impact testing steel
- toughness test forging
- Charpy V-notch
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What does the Charpy test measure?
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Toughness — the energy a material absorbs when fractured by a sudden impact, reported in joules.
Why does test temperature matter?
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Steel becomes brittle below its transition temperature, so testing must be done at the service temperature to be meaningful.
Do you perform Charpy testing?
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Yes, at ambient or specified sub-zero temperatures, with results reported per batch.