A notched cantilever specimen is struck on its notched face by a pendulum; absorbed energy reflects toughness with a different stress distribution than Charpy.
A notched cantilever specimen is struck on its notched face by a pendulum; absorbed energy reflects toughness with a different stress distribution than Charpy.
Formula
KU = E0 − E1
Same energy balance as Charpy with machine-specific friction corrections. Notch and striker geometry follow ASTM E23 Izod configuration; results are not directly interchangeable with Charpy KV values.
The Izod impact test clamps one end of a notched bar as a cantilever and strikes the face containing the notch with the pendulum tip. The notch experiences higher bending constraint near the clamp compared to the three-point Charpy arrangement, altering triaxiality and shifting absorbed energy for the same material and temperature.
Izod historically dominated plastics specifications (ASTM D256) and some metal curricula; structural steel qualification more often standardizes Charpy. When legacy drawings reference both, do not mix databases without correlation work.
Specimen preparation demands a sharp, square notch within tolerance; plastic deformation during notching absorbs energy and lowers reported toughness. Striker alignment and anvil gap must be verified per equipment manuals.
For polymers, Izod distinguishes notched vs unnotched reporting; notched Izod relates to practical stress concentrations in molded features.
Izod impact test systems and Izod testing machines for plastics, polymers, and metals — cantilever notch-bar absorbed energy per ISO 180, ASTM D256, and ASTM E23 Izod methods. Vector configures pendulum impact testers from 5.5 J to 50 J (and higher-energy metals options) to your laboratory.
Series: Izod
Charpy impact test systems and Charpy testing machines for metals — absorbed energy, notch toughness, ISO 148-1 and ASTM E23. Vector designs manual, semi-automatic, and robotic Charpy lines from 300 J to 750 J, including sub-zero Charpy, tailored to your laboratory.
Series: Charpy
Normalize Charpy or Izod absorbed energy to impact toughness aK using ligament area beneath the notch.
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