A SCHEMATIC OF THE APPARATUS needed for a basic test is shown in Fig. 19 (see Section 4). For the test used as an example here, the specimen is an HY80 structural steel alloy tested at room temperature as part of an E 813 multispecimen JIc investigation. In Fig. 26, the specimen is shown mounted in test clevises with the clip gage installed. In this case, the small-hole specimen (see Fig. 11, design for pin 0.188W, in Section 4) is used with spot-welded razor blade knife edges.