ISO 179-1 is an ISO test method for determining the Charpy impact strength of plastics under defined, pendulum-impact conditions using a non-instrumented setup.
Because Charpy impact results depend heavily on specimen type, notch condition, and test configuration, it’s important to align your lab setup and reporting to the exact version cited in your customer or internal requirement—if you want help matching your need to the right configuration, talk with our team.
ISO 179-1:2026 — Plastics — Determination of Charpy impact properties — Part 1: Non-instrumented impact test
ISO 179-1 specifies a non-instrumented Charpy pendulum impact method for plastics. It is used to generate comparative impact-strength data under defined conditions and to help characterize brittle versus tougher behavior within the limits of the method.
Quick definition
What it is: A non-instrumented Charpy pendulum impact test method for plastics.
What you get: Charpy impact strength values determined from the pendulum energy absorbed to break the specimen in a defined configuration.
Why it’s used: Comparing impact performance across materials, grades, processing conditions, and notch/specimen configurations.
What This Standard Covers
ISO 179-1 describes how to determine Charpy impact strength for plastics under defined test conditions using a non-instrumented pendulum impact tester. It includes multiple specimen types and test configurations, and it varies key test parameters based on the material, the specimen, and the notch condition.
Practically, ISO 179-1 is commonly used when you need a repeatable, standardized impact-strength result without capturing a full force–time or force–deflection curve.
Why This Standard Matters in Testing
Impact performance is often a go/no-go property for plastics used in housings, components, and molded parts that may see drops, knocks, or sudden loading. ISO 179-1 provides a consistent way to compare materials and processing effects using a widely recognized Charpy approach.
For procurement and QA/QC teams, ISO 179-1 test results are frequently used to support supplier comparisons, incoming material verification, and product-change control (resin change, regrind content, molding condition shifts, etc.).
Common Materials, Product Types, or Applications Covered
ISO 179-1 is typically applied to plastics across a wide range of product sectors where impact resistance is important, including:
- Injection molded and extruded plastic materials evaluated using standard test specimens
- Engineering thermoplastics and filled/reinforced compounds where notch sensitivity may be important
- Material qualification and comparison programs (R&D screening, grade selection, supplier benchmarking)
Because the standard allows different specimen and notch configurations, the specific setup used in your requirement strongly influences what the result means and how it compares to historical data.
Common Test or Verification Workflow
A typical ISO 179-1 workflow in a plastics lab includes specimen preparation, conditioning, and non-instrumented Charpy pendulum impact testing using the specified configuration.
Common workflow elements: Define the required specimen type/configuration and notch condition, condition specimens as required by the test plan, verify key dimensions, select a pendulum energy range appropriate for the expected break energy, perform impacts, and report impact strength results with the configuration details needed for traceability.
Equipment Commonly Used for This Standard
ISO 179-1 generally points to a Charpy pendulum impact testing setup capable of running the required specimen and support configuration with consistent striker geometry and repeatable release/impact conditions.
Common equipment: Non-instrumented Charpy pendulum impact tester, Charpy supports/anvils and striker(s) appropriate to the cited configuration, specimen centering and alignment aids, dimensional measurement tools (e.g., calipers or micrometers), and (when notched specimens are required) a notch preparation solution suitable for plastics specimens.
Practical selection note: Equipment choice is usually driven by the required pendulum energy range, the permitted specimen/configuration options in the cited version, and how your lab needs to handle brittle vs. tougher materials without saturating low-energy readings or bottoming out the pendulum capacity.
How to Read This Designation or Revision
ISO 179 is the Charpy impact properties series for plastics, and ISO 179-1 identifies Part 1 covering the non-instrumented impact test method.
The year matters: Citations such as ISO 179-1:2026 indicate a specific published edition. Test configurations, parameter options, and reporting expectations can change between editions, so contracts, drawings, or customer specifications should be followed exactly as written.
Related Standards, Methods, or Frameworks
Depending on your reporting needs, you may also see ISO 179-1 used alongside other impact methods or companion documents.
Common related references: ISO 179-2 (instrumented Charpy impact test) when a force–deflection or force–time curve is needed, and ISO 180 (Izod impact strength) when the program specifies an Izod configuration instead of Charpy.
Get help selecting an ISO 179-1 test setup
If you’re specifying a pendulum impact tester for ISO 179-1—especially when you need to cover multiple materials or both notched and unnotched conditions—you can request a detailed quote for a configuration matched to your energy range, fixtures, and lab workflow.