scope:

This method covers the determination of the plane-strain fracture toughness of me­tallic materials by a bend or a compact ten­sion test of a notched and fatigue-cracked specimen having a thickness of 0.25 in. (6.4 mm) or greater.

NOTE I-Plane-strain fracture toughness tests of thinner materials that are sufficiently brittle (see 6.1) can be made with other types of specimens ( IJ.' There is no standard test method for testing such thin materials.

The bend specimen is a single-edge notched beam loaded by three-point bending.

The compact tension specimen is sin­gle-edge notched and pin loaded in tension.

The specimen size required for testing purposes increases as the square of the ratio of toughness to yield strength of the material, therefore a range of proportional specimens is provided.

NOTE 2- The values stated in U.S. customary units are to be regarded as the standard. The metric equivalents of U.S. customary units may be approx­ imate.