Article discusses issues related to the weakened strength of the joints in conveyor belts. Joints are the weakest element of the belt and should be taken aimed at eliminating the errors made that may be caused by multiple factors. Every breakdown generates additional costs in the company so this is important to decrease their number. All analyzed joints were made using belts with steel cords. The results were obtained from the Conveyor Transport Laboratory at the Wroclaw University of Technology. The assessment showed a significant impact of the working defects on joint strength. Also the trend analysis performed on the samples of regenerated belts showed a linear decrease in strength along with the degree of regeneration.