This paper proposed solutions for profiling the disc tool in machining a helical cylindrical surface with constant pitch. A section method has been developed in AutoCAD environment together with a Boolean operation. Especially, this work presented a computational problem of determining the any section of a helical surface, while other documents only refer to the section along axis and cross section. The authors used a combinative method of analytics, graphics and programming to solve that problem, applying in designing cutting tool for machining helical cylindrical surfaces. The proposed method has been implemented and verified through subroutines written in Visual C running in AutoCAD. The testing results have confirmed that the proposed methods achieve high accuracy for variant profiles of helical surfaces in short time conputation.
