Charpy Impact Test for Plastics (ISO 179) | Kiyo R&D Lab

Charpy Impact Test — Toughness Testing to ISO 179 | Kiyo R&D Lab

Charpy Impact Test for Plastics — Kiyo R&D Lab

How much sudden shock can your plastic absorb before it cracks? A brittle failure under impact can turn a good design into a warranty problem overnight. The charpy impact test measures exactly that — the energy a material absorbs when struck by a swinging pendulum — giving you a clear number for toughness. Kiyo R&D Lab tests the impact resistance of your plastics to ISO 179 with accuracy and confidence.

From rigid thermoplastics and filled compounds to composites and moulded parts, our expert team delivers accurate impact data, supporting analysis, and clear, audit-ready reports you can rely on.

Charpy Impact Test for Plastics (ISO 179) | Kiyo R&D Lab

What Is the Charpy Impact Test?

The charpy impact test measures how much energy a material absorbs when it is struck by a swinging pendulum hammer. A specimen is supported horizontally as a simple beam, and the pendulum strikes it in the middle. The energy lost by the pendulum in breaking the sample — read from how high it swings afterwards — is the impact energy, a direct measure of toughness.

For plastics, the method follows ISO 179. Specimens can be notched or unnotched, and struck edgewise or flatwise, because a notch concentrates stress and reveals how the material behaves when a flaw or sharp corner is present. The result tells you whether a plastic is tough or brittle under sudden load.

What We Measure & Uses

Our charpy impact test service captures the impact behaviour your specification calls for, in the configuration that matches your product.

Impact Energy

Energy absorbed at break.

Impact Strength

Energy per cross-section.

Notched & Unnotched

With or without a notch.

Edgewise / Flatwise

Strike orientation.

Ductile / Brittle

Failure behaviour.

Batch Comparison

Lot-to-lot toughness.

ISO 179 Configurations

DesignationConfiguration
ISO 179-1Instrumented / non-instrumented
eA / eB notchNotched, edgewise
UnnotchedEdgewise or flatwise
ResultkJ/m² impact strength

Exact specimen and notch type follow ISO 179 and your specification.

Who Uses This Test

  • Plastics Manufacturers: Toughness & grade verification — a core use of this method.
  • Product Designers: Confirming impact resistance for a part.
  • Automotive & Consumer Goods: Durability under shock.
  • Compounders: Effect of fillers & additives on toughness.
  • QC & R&D: Meeting datasheet impact values.

Charpy vs Izod & Standards

The charpy impact test and the Izod test both use a swinging pendulum, but they hold the specimen differently — a key distinction when your specification names one or the other.

ISO ASTM

AspectCharpyIzod
Specimen heldHorizontal, both endsVertical, clamped one end
Notch facesAway from the strikeToward the strike
Plastics standardISO 179ISO 180 / ASTM D256
Result unitkJ/m²kJ/m² or J/m

Need Izod instead of Charpy? We run both — if your buyer specifies ASTM D256 (Izod), we can test to that too. Ask us which method fits your specification.

Serving Chennai & Tamilnadu

Based in Chennai with branches in Chrompet and Oragadam, Kiyo R&D Lab makes plastic impact testing easy to access for the Chennai–Oragadam industrial corridor, with convenient drop-off and courier-friendly collection.

Kiyo R&D Lab — Chennai (Chrompet & Oragadam)

Looking for a charpy impact test? Our facilities measure the impact strength of plastics to ISO 179, notched or unnotched, with clear, accurate reporting.

Call 90420 86986 Request a Quote

Explore all our capabilities at www.kiyorndlab.com.

Charpy Impact Test for Plastics (ISO 179) | Kiyo R&D Lab

Know Your Material’s Toughness — Kiyo R&D Lab

Impact resistance decides whether a part survives a drop, a knock, or a sudden load. With an accurate charpy impact test, we combine correct specimen preparation, the right notch and orientation, and expert interpretation to give you toughness data you can stand behind.

From a single impact check to a full mechanical profile across tensile, flexural, and impact, the team at Kiyo R&D Lab is ready to help. Reach out today and turn your sample into a reliable, audit-ready report.

Frequently Asked Questions

What does the charpy impact test measure?
It measures the energy a material absorbs when struck by a swinging pendulum — a direct measure of toughness. A high value means the material absorbs a lot of energy before breaking; a low value means it is brittle.
What is the difference between Charpy and Izod?
Both use a pendulum, but Charpy supports the specimen horizontally at both ends and strikes the middle, while Izod clamps it vertically at one end. The notch also faces different directions. For plastics, Charpy follows ISO 179 and Izod follows ISO 180 or ASTM D256.
Why is the specimen notched?
A notch concentrates stress at one point, mimicking a real flaw, sharp corner, or moulding defect. Notched results show how the material behaves when a stress raiser is present, which is often more relevant to real-world failure than an unnotched value.
What units are the results in?
For plastics under ISO 179, Charpy impact strength is reported in kilojoules per square metre (kJ/m²), which normalises the absorbed energy by the specimen’s cross-sectional area so results can be compared.
Which should I choose, Charpy or Izod?
Follow whichever your specification or customer names. If you have a free choice, the charpy impact test is common for plastics under ISO standards, while Izod is common under ASTM. We can run both and advise on which suits your material.
How do I get started?
Simply request a quote on WhatsApp or visit www.kiyorndlab.com, tell us your material and notch requirement, and we’ll guide you through the rest.
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