In this paper, numerical, analytical, and experimental investigations were undertaken in order to clarify the influence of friction in tubular channel angular pressing (TCAP) as a severe plastic deformation technique for producing nanostructured pipes. The effects of different Cou- lomb friction coefficients of 0, 0.025, 0.05, 0.075, and 0.1 on the deformation behavior and re- quired load were investigated using the finite element method (FEM). The results showed that the friction coefficient in the TCAP has a significant effect on the required load due to the variation in the friction force during the TCAP. A comparison between the FEM and experimental results showed that the Coulomb friction coefficient is approximately 0.055 in the TCAP process when MoS 2 was used as a lubricant. The analytical investigation results in the calculation of the equiva- lent plastic strain were close to those of the FEM when the friction coefficient increased from 0 to 0.1. The die corner gap in shear zone III decreased with the increasing friction coefficient.