Izod Pendulum Impact Tester
Vector pendulum impact tester for Izod absorbed energy on plastics, polymers and metals per ISO 180, ASTM D256 and ASTM E23 — from 5.5 J to 50 J.
- astm-e23
- iso-148-1
- +1 more
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A notched cantilever specimen is struck on its notched face by a pendulum; absorbed energy reflects toughness with a different stress distribution than Charpy.
Impact testing
Izod Impact Test
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.
Related standards
Compatible equipment
Related calculator
Compute pendulum absorbed energy, machine capacity, and impact strength (kJ/m² or Izod J/m) from Charpy or Izod test inputs per ISO 148-1, ASTM E23, ISO 179-1, and ASTM D256.
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