Abstract: The Sink Field Method（SFM） has been shown to be an acceptable theoretical method for blank development. The autosegment of the outline of a irregular drawn part is investigated in detail in SFM.
The blank contours of some irregular drawn parts are given, which are autotracked with the help of SFM computer program.The blank contours of some typical drawn parts autotracked by SFM are tested with drawing process. Based on the test results, guiding function of SFM for arranging drawing beads is discovered, and the accuracy of SFM for blank development is shown theoretically to be improved by adjusting the sink distribution.