The Double-Ligament Test has been successfully used in the past to solve a number of practical problems relating to the ductility in the Z-direction of a variety of wrought and cast products, although much of the early experience was generated with high-strength low-alloy steels. More recently the test has been applied with considerable success to the evaluation of the through-thickness properties of forged and cross-rolled electroslag remelted AISI 4340 steel in the quenched and tempered condition with yield strengths in the vicinity of 2000 MPa (290 ksi). This paper describes the precautions necessary in testing steels of this particularly high strength-hardnes-sductility level, and compares tensile properties of this type of material at three product thickness levels for all three principal directions. A comparison is also made between the properties determined using this test for longitudinal and transverse directions, with these employing conventional-type test bars. The paper concludes with a discussion of the results obtained and their interpretation using SEM-based fractography and other appropriate techniques.