Chatter is a significant issue in milling processes, affecting part quality and productivity. Higher cutting speeds are required to obtain deeper stability lobes with standard end mills in order to improve output. Higher cutting speeds are not possible in cutting hard-to-cut materials due to machine tool and machinability restrictions. Special milling tools, such as variable pitch and crest-cut cutters, provide an alternate way of increasing productivity in these situations. Crest-cut tools create wide stable zones at low speeds due to their unique geometry. The crest-cut tools' cutting edges have a wavy edge shape, which gives them this benefit. The semi-discretization method is used in this study to investigate the stability of crest-cut tools. The effect of edge wave geometry on stability is investigated and compared with standard tools using the proposed model, which is experimentally verified. Results show that the crest-cut tools introduce significant advantages in terms of stability limit and stable zones compared to standard end mills.