[en] The application of elastic-plastic fracture mechanics to safety analysis of pressurized vessels has been developed based on limited, published finite element solutions. These limited solutions have not necessarily been verified to be accurate. This paper presents new, accurate, finite element solutions. These solutions are based on ABAQUS fully-plastic finite element J-integral solutions presented in terms of calibration constants, h₁. These calibration constants are a function of crack depth to thickness, aspect ratio of the flaw, Ramberg-Osgood hardening exponent, and thickness to inside radius ratio. An evaluation of the published J-integral solutions lead to the conclusion that these earlier solutions were not taken far enough out in applied pressure to produce valid fully plastic J-integral solutions. This is shown to produce higher, more conservative h₁ values than are presented in this paper. In addition to comparisons with these published results, the effect of strain hardening was examined. The earlier work was limited to a strain hardening value of n = 8.6. The work presented here includes the range of values of n = 5, 7, 8.6, and 10 representative of both austenitic and ferritic pressure vessel and piping steels. 12 refs., 3 figs., 5 tabs