O&K Mining GmbH (today Terex GmbH) was founded in 1876 by Benno Orenstein and Arthur Koppel. O&K has always pioneered progress and in 1961 was the first company in Europe to produce all-hydraulic excavators. The company then applied all its efforts in the production of bigger and bigger machines, extending nowadays to the world's largest hydraulic excavator, the 1000 t heavy RH 400. Electronic control and monitoring systems are another area in which O&K has played a leading role.
Since April 1, 1998, O&K Mining GmbH has been a part of the Terex Group. TEREX is a world leader with a broad-based range of articulated and rigid trucks, coal trucks, scrapers, and hydraulic excavators. Within the Group, Terex Mining specializes on digging and haulage machines that operate in quarries and open-cast mines.
Eltrak Bulgaria is an authorized dealer for Terex O&K hydraulic excavators since 2006.