This article presents method and results of studying on influence of some main technological parameters such as stitching density, sewing threat tension and presser foot pressure on the sewing strength after sewing and after abrasion 1000 cycles by standard IUP 450. In this work we used the orthogonal experiment delineation method, DesigningExpert6.0 software for data treatment. The experiment regression functions between the three technology parameters and the sewing strength after sewing and after abrasion were built. From these functions, the optimal technological parameters for sewing good strength and good looking seams of protective footwear uppers suitable for using in hard and hot environment of steel industry were determined.