The aim of the monograph was to select the steel grade and to develop the technological cycle of manufacturing high-strength mandrels for piercing and cross-rolling of seamless pipes. As a result of development of manufacturing technology and processes of heat treatment of screw piercing mandrel the optimal steel grade 4 5 1 for mandrels production was selected, which provides the best combination of price and quality; the mandrel manufacturing technology was designed, the scheme of technological processes of product manufacturing was developed; special heat treatment to prevent defects -...