The textile manufacturing industry is quite traditional and therefore maintains a certain level of production based on empiricism. Research on textile materials and production processes has been gaining strength mainly motivated by professional sport. However, with regard to the most common processes, there are few studies that serve to demystify some information that is transferred over time. The present work performs a resistance analysis of the seams applied in flat fabrics commonly used in the making of uniform trousers. The purpose is to identify whether the Double Chain Stitch Sewing Machine is stronger than that of the Interlock Sewing Machine with rebound stitch in the Twin Needle Lockstitch Sewing Machines. For this purpose, tensile tests were carried out, where the sample tested was the twill, 3x1 frame with 100% cotton composition tested in the different directions of the fabric (weft, warp and bias). The results show that the Interlock Sewing Machine is stronger than Double Chain Stitch Sewing Machine. The results indicate that the strongest seam is necessarily the one that uses the least needles and this goes against the information that the manufacturers thought as well as spending less resources to perform.