ASTM E23 — Notched Bar Impact Testing of Metallic Materials (Charpy & Izod)

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ASTM E23 is the core set of test methods for notched-bar impact testing of metallic materials using Charpy (simple-beam) and Izod (cantilever) configurations. It defines how absorbed energy is measured to judge toughness. To match this to your program, talk with our team.

What ASTM E23 Covers

The method drops a pendulum onto a notched bar and records the energy absorbed as it fractures, a direct measure of a metal toughness and its ductile-to-brittle behaviour with temperature. Both Charpy and Izod arrangements are defined.

Specimen Notch Types

E23 specifies notched specimens, most commonly the V-notch, and sets their geometry precisely:

Table 1. Common Charpy specimen notches in ASTM E23.
Notch Use
V-notch The most widely specified toughness test
U-notch (keyhole) Used where a legacy or specific requirement calls for it

Why It Matters

Charpy energy underlies toughness acceptance for structural steels, pressure equipment, and pipelines, often at specified low temperatures. Accurate, verified machines and correct specimen preparation keep the numbers defensible.

Reading the Designation

Cited as ASTM E23-YY. Confirm the edition, notch type, and test temperature. To configure impact testing, request a quote.

Related Standards

ISO 148-1 is the ISO Charpy method, ASTM E2298 adds instrumentation, and ISO 148-2 verifies the machine.

Request a Quote

Setting up Charpy or Izod impact testing of metals? Request a quote and our team will help you build a system matched to your specimen type and test temperature.


TensileMill CNC products for ASTM E23

Our specimen-preparation systems and testing equipment compatible with ASTM E23:


Configure your ASTM E23 setup with TensileMill CNC

Adding capacity or replacing older equipment? TensileMill CNC can support your ASTM E23 program. That typically means CNC systems for flat and round impact specimen preparation with precision notching. Send us your specimen types and target standards, and we will help you spec the right system.