Abstract: Described in the article is a calibration device that is especially designed for the Ф76 mm less stand 3-roll mandrel mill employed for producing small-sized pipes.Pressure of the calibration cylinders is obtained based on stress state analysis of the cartridge and the zeroing stand, and a finite element analysis(FEA)of the centering piece.Thanks to the ex-works integration testing and the on-the-site application, the design of the calibration stand is verified, and the reasonability of pressure determination of the hydraulic cylinders proved.