Science and Education Publishing American Journal of Mechanical Engineering 2328-4110 3 4 2015 07 20 A Method of Calculus of Residual Lifetime for Lifting Installation 115 121 EN Cătălin Iancu Engineering Faculty, University “Constantin Brâncuşi” of Târgu-Jiu, Romania Florin Vîlceanu AJME2015342 10.12691/ajme-3-4-2 2015 04 21 2015 07 08 2015 07 20 In this paper a method of calculus is presented step-by-step in order to establishing the residual lifetime of a lifting crane, using non-destructive methods of study. First it must be establish the actual state of machine and also areas subject to study, and then by applying the method it can be drawn the conclusion that at 2/3 of initial load can be reached an extension up to 5 times of actual residual lifetime.