The character of emerging surface defects is directly related to the technology of manufacturing metal products at each metal conversion. Star, netted, and transverse cracks are the defects that are the most significant and hardly removable in the continuous casting of steel in what considers the quality of surface. We applied optical and scanning electron microscopy to accurately determine the place of and reason for the emergence of netted cracks. The results obtained by metallographic examination of hot-rolled 140-mm round blank parts, continuously cast ingots, and "top crusts" of smaller and larger facets enabled us to determine that the sites were netted cracks emerging and excluding the adverse effects in casting metal that result in the occurrence of defects.

Relevance: the increase in the number of destruction of welded joints of the metal wire cord due to discrepancies in the microstructure of the welded seam.Purpose: to find the roots of defects in welded joints of metal wire cord to reduce the number of inconsistencies in this parameter and study the features of the formation of the microstructure of welded joints.Methods of research: as a material for research the metal wire cord of various designs made in steel – wire shop No. 2 of OJSC «BSW – Management Company of Holding «BMC» – a rod of own production was applied; the study was conducted using a Nikon SMZ 1000 stereoscopic microscope with a video system and an inverted metallographic microscope OLIMPUS GX-51 with a video system; measurement of hardness was carried out according to Vickers with a load of 0.5 kg on a hardness testing ZWICK 3Х5624АТ.Research results: the regularities and causes of the formation of mismatch of the microstructure of welded joints during welding on metal: incorrect setting of the welding machine (slowing down of the welding carriage); mismatch of the tempering temperature (a faulty button or operation home run twice); a small dwell time in the terminals (jaws) for tempering; inadequate execution of Regulation of the welded connection of the operator’s actions (pass or failure of the operation «tempering of the weld»); influence of external environmental factors (microclimate) of the operator’s workplace.

Analysis of the research results shows that about 20% of defective weld joints of the metal wire cord are destroyed due to the presence of internal pores in the weld zone. The article analyzes the results of the work carried out in the laboratories of the Belarusian metallurgical works – the management company of the Belarusian metallurgical company holding, and identifies possible causes of this defect in the structure of welded metal wire cord joints.

High pressure hose (HPH) is a flexible pipeline for the transportation of special hydraulic and motor fluids based on mineral oil, liquid fuel, grease or water emulsion under pressure, to transfer the working force. Structurally, the sleeve is two or more rubber tubes placed one into the other, reinforced with metal braids or coils, equipped with connecting fittings [1]. HPH is characterized by a sufficiently high flexibility in combination with the ability to withstand significant pressure.In cases of premature failure of high-pressure hoses during cyclic or impulse tests, the cause of the nonconformity must be determined. The article describes the main stages of the study of defective high-pressure hoses in determining the cause of their failure and provides examples of studies using visual, metallographic, electron microscopic methods of analysis in the metallographic laboratory of OJSC «BSW – Management Company of Holding «BMC».

Technical measurements of linear-angular sizes of parts and products are the most common in mechanical engineering and make up to 95% of the measurements of all controlled sizes. Measuring control is an integral part of each operation of technological processes of production, assembly, testing of products. The complex method of measuring the external and internal geometric characteristics of a carbide die, given in the article, allows to measure the geometric parameters of small-size parts and to give a final assessment of the product for compliance with the requirements of the project technical documentation.