Overview
EN ISO 148-1:2016 - Metallic materials - Charpy pendulum impact test - Part 1: Test method defines the standardized procedure for Charpy pendulum impact testing of metallic materials using V‑notch and U‑notch specimens. The standard specifies how to determine the absorbed energy (KV, KU) during a pendulum impact after correction for friction. It covers specimen geometry, test equipment, the test procedure, post-fracture inspection and reporting. Instrumented impact testing is explicitly excluded (see ISO 14556).
Key topics and technical requirements
- Scope and purpose: Measurement of energy absorbed in a single-blow pendulum impact on standard Charpy specimens (V‑notch and U‑notch).
- Specimen definitions: Terms such as width (W), thickness (B) and length (L) are defined; 2016 edition aligns terminology with other fracture standards.
- Notch geometry: Requirements for V‑notch and U‑notch preparation, tolerances and specimen marking.
- Test equipment and verification: Requirements for pendulum machines, striker geometry, installation and periodic verification (see ISO 148‑2 for machine verification).
- Test procedure essentials: Principles of the test, friction measurement and correction, specimen transfer, temperature control, handling incomplete fractures and jammed specimens, and post‑fracture inspections (fracture appearance, lateral expansion).
- Reporting: Mandatory and optional information to include in test reports (absorbed energy values, test temperature, specimen ID, machine details).
- Informative annexes: Additional guidance on self‑centring tongs, lateral expansion, fracture appearance, energy vs temperature curves (transition temperature), and measurement uncertainty. Annexes B and C are adapted from ASTM E23 with permission.
Practical applications
- Material toughness assessment: Evaluate ductile-to-brittle behavior and compare materials under impact loading.
- Quality control and acceptance testing: Routine checks in steel production, heat treatment, welding and fabrication processes.
- Design and safety: Support material selection and fracture-critical design decisions in construction, pipelines, automotive and heavy industry.
- Research and development: Characterize new alloys, treatments and joining methods for impact resistance.
Who uses this standard
- Test laboratories and inspection bodies performing Charpy tests
- Steelmakers, metallurgical labs and heat‑treatment facilities
- OEMs, fabricators and construction firms requiring material toughness data
- Certification organizations and procurement engineers specifying impact properties
Related standards
- ISO 148-2 - Verification of Charpy testing machines
- ISO 148-3 - Preparation and characterization of specimens for indirect verification
- ISO 14556 - Instrumented impact testing (different method)
- ASTM E23 - Source for annex material on fracture appearance and reporting
This standard is essential for consistent, reproducible Charpy pendulum impact testing and for ensuring comparable toughness data across laboratories and industries.
