The device has offset axis 2 and angle compensation modules (3) in the vertical axis (4) of a test machine positioned in series between the loading frame and clamping fixture (7) for a specimen. The off-set axis module consists of two bodies (18/19) supported so that they can move relative to one another in a horizontal plane. The off-set angle module consists of a sphere (11) which can rotate in a spherical shell (9/10). The bodies which can move relative to one another can be joined together by pre-stressing them and the pre-stress force can be reduced can be reduced
