ASTM E812-91(1997) PDF

1.1 This test method covers the determination of the crack strength [sigma]c of a Charpy-type specimen (see Fig. 1) containing a fatigue crack tested in slow bending. The nominal cross-sectional dimensions of this specimen are identical to those given in Test Methods E23 (Fig. 4A) for the standard Charpy test specimen. The crack strength will be sensitive to changes in the plane-strain fracture toughness providing the strength of the specimen is determined primarily by crack propagation and not by plastic instability.