Abstract
Reliability of computer modelling of tube hydroforming depends strongly on mechanical properties of tubes, which are difficult to determine and sensitive to tube production methods. Some developments in experimental set-up and the vision system for tensile tests of specimens cut from the tube in longitudinal and circumferential directions are presented. The high accuracy of results obtained by this system has been crucial for determining strains in tested tubes as well as flow curves for tube material and its planar anisotropy.