ISO 148-1 is the core Charpy pendulum impact test method used to measure the energy absorbed when a notched metallic test piece is broken by a swinging pendulum.
Labs and manufacturers use this method to compare impact toughness, support material qualification, and verify heat treatment or process consistency—especially when results are reported at specific temperatures. If you need help aligning machine capacity, striker setup, and temperature conditioning with your cited edition, you can talk with our team.
Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 148-1 defines a standardized Charpy pendulum impact test procedure for metallic materials using notched specimens. It is commonly referenced for Charpy V-notch (CVN) and Charpy U-notch testing where a single-impact fracture and absorbed energy result are required.
This document is a test method. It focuses on how the impact test is performed and how the absorbed energy result is obtained and reported for the Charpy pendulum method (non-instrumented).
Quick Definition
ISO 148-1 is a Charpy pendulum impact test method for metallic materials that measures the energy absorbed in fracturing a notched test piece under a single pendulum strike.
What This Standard Covers
ISO 148-1 covers the conventional (non-instrumented) Charpy pendulum impact test procedure used to determine absorbed impact energy for metallic specimens with standardized notch types.
In scope: Charpy pendulum impact testing using V-notch and U-notch specimens, with test execution and result reporting focused on absorbed energy.
Out of scope (commonly handled by other documents): Instrumented Charpy impact testing (where force-time or force-displacement signals are recorded) is covered under a separate ISO method.
Why This Standard Matters in Testing
Charpy impact results are widely used as a practical indicator of how a metal behaves under rapid loading and in brittle-to-ductile transition regimes. Because the method is highly standardized, ISO 148-1 supports more consistent comparisons between material heats, product forms, and suppliers when testing is performed at controlled temperatures.
For procurement and QA/QC workflows, the biggest practical impact is that equipment setup (capacity, striker/anvil configuration, and temperature conditioning) must match what the purchasing specification or code citation expects.
Common Materials, Product Types, or Applications Covered
ISO 148-1 is used broadly across metallic materials testing programs where Charpy absorbed energy is a required property or acceptance datapoint.
Common materials: Carbon steels, low-alloy steels, stainless steels, and other structural alloys tested for impact performance.
Common applications: Plate, bar, forgings, castings, weld procedure qualification and production weld testing programs (when Charpy testing is specified), and general material qualification where impact toughness at a defined temperature is required.
Common Test or Verification Workflow
Most ISO 148-1 programs follow a straightforward sequence that ties specimen preparation, temperature control, and pendulum impact testing into a reportable absorbed energy result.
Typical workflow:
- Machine and notch Charpy specimens to the required geometry (V-notch or U-notch, as specified by the calling document).
- Condition specimens to the required test temperature (ambient or sub/above-ambient), using a bath, chamber, or other controlled method as appropriate.
- Verify the pendulum impact tester configuration is appropriate for the expected energy range and the required striker/anvil setup.
- Perform the impact test and record absorbed energy for each specimen.
- Report results in the format required by the invoking specification (often including test temperature, notch type, and the set of individual values).
Equipment Commonly Used for This Standard
ISO 148-1 points most directly to a Charpy pendulum impact testing system and the supporting tooling needed to prepare, condition, and safely test notched specimens.
Common equipment: Pendulum impact testing machine (Charpy), striker(s) and anvils appropriate to the required Charpy configuration, specimen centering/support tooling, energy readout/data capture, and a safety enclosure or guarding.
Common supporting tools: Notch broaching or milling equipment for Charpy specimens, notch inspection/measurement tools, specimen temperature conditioning equipment (cooling/heating bath or environmental chamber), handling tools for conditioned specimens, and calibration/verification accessories aligned with the lab’s verification program.
If you are specifying a new Charpy system or upgrading an existing machine for higher throughput or tighter temperature-control workflow, you can request pricing for an ISO 148-1-ready configuration based on your energy range and specimen handling needs.
How to Read This Designation or Revision
ISO 148-1 indicates Part 1 of the ISO 148 series for the Charpy pendulum impact test.
What the year means: A citation such as “ISO 148-1:2016” identifies the specific published edition year. Many purchase specifications, codes, and customer requirements require a specific edition, so the exact year cited can affect acceptance criteria references, reporting expectations, or verification alignment.
Revision sensitivity: When a contract document cites ISO 148-1 without a year, confirm with the customer or governing specification which edition is intended before finalizing procedures and quoting equipment or verification tooling.
Related Standards, Methods, or Frameworks
ISO 148-1 is often used alongside other Charpy-focused documents depending on whether the need is to run the basic test method, verify machine performance, or capture instrumented signals.
Common related references: ISO 148-2 (verification of pendulum impact testing machines), ISO 148-3 (reference test pieces for indirect verification programs), and ISO 14556 (instrumented Charpy V-notch method).
Get help selecting Charpy impact equipment for ISO 148-1
If you need a Charpy pendulum impact tester, verification accessories, or a temperature-conditioning workflow matched to your required energy range and cited edition, you can request a detailed quote with the key options laid out for your lab.