Abstract: In this paper, the elasto-plastic finite element method is used to evaluate limit loads of the equal-diameter T-junctions of piping with local wall-thinnings under out-of-plane moment. Numerical examples of non-defective equal-diameter T-junctions of piping show that the computed results are in good agreement with available experimental data. The effects of the sizes and positions of local wall-thinnings on the plastic limit loads of equal-diameter T-junctions of piping are investigated. Some typical failure modes of the T-junctions with local wall-thinnings are studied. The results are expected to provide theoretical bases for the structural design and safety assessment of equal-diameter T-junctions of piping with local wall-thinnings.