Add to ORKGThis work aims at the extension of the Probabilistic Theory of Plastic Mechanism Control (P-TPMC) for Steel Moment Resisting Frames (MRFs) to other steel grades. P-TPMC is based on the application of First Order Reliability Method and Ditlevsen Bounds, which represents the reliability method for series systems, considering as random variable the yield strength of steel members. As in previous work, only the S275 steel grade has been investigated in this paper the analyses are extended to a different grade of steel, in particular, S235 and S355, to evaluate its influence on the failure probability of TPMC. Finally, a simple relationship to computing the value of the overstrength factor needed to include the importance of random material vari...