The strength of bonded textile seams to depend upon many factors. Tensile test machines are employed to predict how a material will react under other types of forces. As part of this thesis a device has been designed and manufactured, a gripping device for testing the strength of the bonded materials. To prove the efficiency and accuracy of the device, comparative tests employing the "Lloyd LR5K Plus" tensile test machine were conducted and both the design phase and the results obtained are presented in this paper. The results obtained showed that through the use of the gripping device, a more simple structure, with evenly distributed stress and which does not damage the textile material at the firmly gripped points during testing, has been discovered.