Mannesmann Aktiengesellschaft

Gerhard Kulessa

Ettore Cernuschi

Jurgen Pietsch

Frank Salomon

Walter Randerath

Thomas Leisten

Manfred Proske

A process for producing a hollow billet for producing tubing for antifriction bearings includes massively reducing a bloom in a three-roll rotary piercing mill and subsequently piercing the reduced bloom in a three-roll rotary piercing mill. The reducing and piercing may be performed in one-pass through the three-roll rotary piercing mill. The reducing and piercing steps may also be performed in separate passes through the same mill or through two separate mills.

Process for the production of seamless tubes

A multi-stand roll train for longitudinally rolling seamless steel tubes in a continuous rolling process around an internal die using integrated two-high stands staggered by 90.degree. with correspondingly grooved rollers. The rollers are radially adjustable relative to one another, and at least the rollers of the final roll stand in the direction of rolling are divided along a central plane which vertically intersects the axis of the roller to form two halves. The two halves of the divided roller are axially adjustable relative to one another.

Multi-stand roll train

Growing community of inventors

Munich, Georgia

Gerhard Kulessa