Abstract
The purpose of this paper is to provide the method of conventional stress analysis for a pressurized hydraulic cylinder with internal thread undercut. In the case of hydraulic cylinder with thread undercut, several loads and stresses occur during operating. So, the thread undercut can be most critical section has to be considered in detail for strength check. In this paper, the conventional stress analysis method at internal thread undercut of hydraulic cylinder based on Kowalski's formula is introduced. The method is verified by comparing to FEM analysis results using ANSYS.