Abstarct: The study of friction in the sheet mextal forming is important because of its significant effects on dimensional accuracy, product surface quality, required power, and energy. Having the sufficient knowledge about the contact friction and how it affects the abovementioned parameters will greatly help the modeling and designing of process. In this research, an analytical-numerical-experimental study of friction coefficient in stretch forming of DC04 steel sheet as a widely used raw material in the automotive industry has been carried out. In the experimental stage, by performing a uniaxial tensile test at angles of 0 °, 45 °, and 90 ° with respect to the rolling direction, the plastic anisotropy coefficients, the constants of the power-law model, and other mechanical components of the material were obtained. Then, by presenting an analytical method of classical plasticity for the stretch forming, baxsed on the Hill-48 anisotropic yield criterion and the associated flow rule, the stress and strain components in different zones of the blank were calculated. In this method, by deriving the equilibrium equations at the contact surfaces of the sheet with the tooling components, the effect of frictional forces on the stress distribution was investigated using the Coulomb model. Then, the stress distribution, strain, and thickness changes in different areas as well as the forming force were calculated. In the numerical stage, the stretch forming was simulated for two different blanks including cut-out and without cut-out. As a result, two novel friction calibration diagrams were achieved by modeling of processes for six coefficients of friction i.e. 0, 0.1, 0.2, 0.3, 0.4, and 0.5. These two diagrams were related to the magnitude of in-plane strain and cut-out diameter in the deformed blank. After designing and manufacturing the stretch tooling, the stretching of both specimens i.e. with and without cut-out were done by using different lubricants of grease and nylon for various displacements, and the values of strain, stress, thickness, and diameter of circular cut-out were calculated. Consequently, the magnitude of friction coefficients were estimated according to each calibrating diagrams. Finally, the analytical results were acceptably verified by comparing numerical outcomes with the experimental results.