seamless steel tubes of outer diameter 60 - 406 mm and wall thickness 6 - 65 mm, made of carbon and alloy steel, hot rolled by Mannesmann technology, including Line Pipe 6 5/8" - 16" and Casing 9 5/8" - 13 3/8" ( with couplings for threads protection) that conform with the Czech CSN standards or with other, like EN, DIN, ASTM, GOST, NFA, API, etc.