The existing methods of analysis of drawing with a floating plug stated the most favourable angle differences between the drawing die and the plug. In the paper the theoretical analysis is made enabling achieving the possibly minimal diameter reduction at the stated wall thickness reduction. There is discussed tool geometry and a state of stress, which enable stable guidance of the process. The experimental studies with drawing of OF-Cu copper and CuZn37 brass tubes confirmed the results of theoretical consideration.

The method of the calculation of strain distribution is based on the measurements of the displacements along the length and transverse cross-section of the conical working zone. Two measuring methods have been used. In the "classical" method the typical measuring microscope equipped with goniometric table has been used. The second method based on the photogrammetric analysis of the pictures has been elaborated and proved by authors. The special computer program has been elaborated for the photograrnmetric image analysis and the later final results receiving. This method can be recommended as the best for using in the practice of researches carried out at the real object. The experiments carried out during the rolling of condenser tubes using pilgering process show that the each transverse section of input tube is twisted during successive working cycles.