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Edge stress has the following characteristics: (1) Locality – Typically, the meridional bending stress is the greatest among edge stresses, with high peaks at the joints; however, its range of influence is limited, as it decays rapidly as one moves away from the edge. For example, in a cylinder, at a distance of 2.5*（Rδ）^0.5 from the connection point, the additional bending stress has dropped to 5% of the stress peak value. (2) Self-limiting edge stress arises from the elastic restraint between the two sides of a boundary. When its peak value reaches the material’s yield limit, if the material has good plasticity, local yielding occurs at the joint, which relieves the elastic restraint and prevents the edge stress from increasing further. Such local yielding does not cause the container to fail as a whole immediately. It can be seen that the impact of edge stress on container safety is less severe than that of film stress. Therefore, in conventional designs such as GB150, edge stress is not calculated quantitatively; instead, reasonable connection structures, local reinforcement, or stress enhancement factors are employed in the film stress strength formulas to account for the effect of edge stress. However, for high-strength steel containers with poor plasticity, or those in which the material tends to become brittle due to handling conditions and where fatigue failure is the primary mode of failure, it is necessary to calculate the edge stress using the stress classification design method. At this point, the edge stress is classified as a secondary stress, and a higher allowable stress value is used for limitation.