New way for defining of main process parameters procedure in the strip ironing process with double side thinning, as well as appropriate experimental results are presented in this paper. Given is improved analysis for friction coefficient and contact pressure defining. Classical common so called "Schlosser model" and other similar models are not suitable in certain cases, and give unreal values for both of main process parameters. Expressions obtained here were verified in suitable examples which are, also, presented in the paper. Verification was performed on the base of experimental results. Realized was the single and four phases ironing process of mild steel DC04 in sheet stripes drawing test. Stripes were 20 mm wide and 2.5 mm thick. Lateral force intensities were 5, 10 and 15 kN. Maximal obtained thinning deformation in one phase was about 17 %. Appropriate lubrication with mineral oil and grease was used in conditions of lower speed of 20 mm/min. Results shows that proposed improved procedures enables more precise process monitoring and precise quantification of lateral force, contact pressure and thinning strain influence on friction.