In the present investigation, the effects of the initial temperature of the sheet, tool diameter and vertical pitch on the final temperature, drawing depth, forming limit diagrams and thickness reduction, resulted from warm incremental forming of titanium sheets are investigated using the Taguchi method. The geometry of a truncated cone with varying wall angle was used for further reduction in the necessary experiments, materials and time. It was shown that any growth in the initial temperature of the sheet or vertical pitch would enhance the formability of the sheet due to the metal softening. The vertical pitch was also the main factor in increasing the final temperature, whereas the tool diameter was the most effective parameter for improving the drawing depth, the average of the major strains and thickness reduction. Moreover, the Sine law was applicable for estimation of final thickness of the incrementally deformed sheets.
