The loads on the tools (bits) were tested in a series of experiments in combination with screws of strength class 8.8 (M6), head height 4 mm. The round head-profile of the screws was milled in order to fix the screws in a shaping template so that they are stable against rotation. With a tightening torque of approx. 30-34 of the Hexalobular (T30) drive and 40-42 Nm of the TOBI drive initial deformations of the head geometry occurred. The immersion depth of the bits was 2.7 mm. The TOBI drive tool has no deformation phenomena. The Hexalobular T30 shows strong deformations in the area of the drive surfaces.