Materials are evolving today faster than at any time in history. In nowadays developing a technique and technology considerably enlarge the exposure of the applicable materials, new materials are created still with much better mechanical and technological properties. Their development and prevalence quickly increase. Today wide use such materials that still recently call by future materials. In the several responsible engineering industry, as well as instrument engineering and other industries do better with “high – performance” composites, new engineering ceramics, high – strength polymers etc., what had previously been done with metals. Choosing of materials is very important in several engineering industries, construction and instrument engineering industries, for example, crash of bench constructions is one of the reasons that the engineer who designed them used wrong materials or did not understand the properties of those used. Therefore for rational utilization materials, we need to know not only their properties, but also need understand factors, witch provides this properties. Therefore we should know how to select materials which best fit the demands of the design – economic and aesthetic demands, as well as demands of strength and durability. Choice of materials of pressure originated details, as also many manufacturing of other important details, which is one of the most actual problems in nowadays. First of all this article shows advantages and disadvantages of the conditions of materials choice of pressure originated details in. The most rational conditions of materials choice, way how to eliminate possibility mistakes, witch can lead down to different difficulties are given for the manufacturing of the definite group of details. There is an example witch describes conditions of materials choice for oil flooded screw compressors. The denotations of different standards of the utilized materials are analyzed in this article. As well as the economic parameters of the various materials in the manufacturing of the oil flooded screw compressors are analyzed. At the end of the article are given possibilities of the improving of materials. We can achieve improving of materials with different materials processing methods, which I had analyzed, for example, using mechanical, thermal, thermal-chemical processing or using different surfaces covering. In nowadays thermal processing method based on metal physic, dislocation theory and changes of metal structure regularity. These processing methods improve physical and mechanical properties of materials.