TWI Frequently asked questions
The ASTM E23 Charpy test differs in one important respect from the BS EN 10045-1 test, namely in the design of the striker. The ASTM striker has an 8mm radius tip compared with a 2-2.5mm radius tip for the BS EN striker, along with many other national standards. Consequently, for materials with a high Charpy energy (above approx. 100J), more energy will be absorbed by the ASTM striker than by the BS EN equivalent and tests carried out to ASTM will report higher impact energy.
The British standard BS 131: Part 6 (1998) describes 'precision' Charpy testing, which allows the option of using either an 8mm striker similar to the ASTM E23 design, or a 2-2.5mm striker similar to that used in BS EN 10045-1.
