Triaxial extension tests were carried out on hollow cylinder sand specimens of identical external geometry under identical test boundary conditions. For reference, solid cylinder sand specimens were tested under identical boundary conditions. The radial width of the hollow cylinders was varied and the test parameters of specimen strength and deformation were found to vary systematically with the specimen radial width. The hollow cylinder extension strengths were significantly lower than the corresponding solid cylinder strengths. In the extreme case, a difference in shearing angle values of 11° was found. However, the behavior of these specimens was found to be quite consistent, when allowance was made for energy spent in volume dilatation and approximately constant frictional strengths were obtained, independent of specimen configuration. The differing modes of behavior of the hollow cylinder sand specimens is considered to be an inherent property of the specimen configuration and this finding has important implications for the interpretation of the conventional extension test.Method of test specimen fabrication and the test procedures are described as well as the hollow cylinder apparatus and an internal load transducer which was used for the measurement of the axial load in these experiments.