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Nowadays is important to increase power efficiency in the heat production sector. Tubes with shaped internal surface are one of the possibilities to improve efficiency of heat exchangers. In the fact of this is actual to look on the improvements of the process of forming from the perspective of the tool construction. Presented article is focused on mechanical analysis of the rotating mandrel for cold forming of tubes with shaped internal surface. As a proposed material of the tool was selected heat-treated tool steel. Analyses were performed with selected configuration of the bearings. One bearing was configured as radial and second bearing was configured as radial-axial. A result shows stresses in the mandrel and deformation of the mandrel under a load of forming pressure. Obtained results have potential to enhance knowledge in the area of construction of the forming tools.

This article deals with examination of the mechanical properties of Damascus steel. Damascus steel is steel used for blades or knives – similar to the past (Damascus steel was a type of steel used for blades in the Near East – made from wootz steel – imported from India). This steel is characterized by significant patterns. The aim of the present study is to point out the laborious method of Damascus production, and to compare the mechanical properties of the initial Damascus steel layers comparison with whole reference Damascus material steel itself.