One-pass is a term used to shape parts without the need for consecutive cuts in machining. Therefore, it is a method to enable cost-effective machining. However, generating the tool geometry and path for a given volume by one-pass milling may rarely be possible. Although the generation of the machined part surface in machining has been widely discussed in the literature, the investigation of such inverse problems is very few. In this paper, helical external grooves were considered. It was demonstrated that it is possible to perform one-pass milling for helical grooves in most cases using a dedicated form cutter. The profile of the form cutter based on the groove profile was derived by an iterative approach using Python programming language. It was considered that the form cutter is the composition of the circles, and the trace of each circle must be in contact with the groove profile in a reference plane. The diameter of each circle was derived using this contact condition. Then, the circles were combined to create the form cutter. Several groove profiles were investigated, and the profiles of the form cutters were obtained. Experimental verification was presented for one of the examples.