O&K

Orenstein & Koppel (normally abbreviated to "O&K") was a major German engineering company specializing in railway vehicles, escalators, and heavy equipment. It was founded on April 1, 1876 in Berlin by Benno Orenstein and Arthur Koppel. Originally a general engineering company, O&K soon started to specialize in the manufacture of railway vehicles. The company also manufactured heavy equipment and escalators. O&K pulled out of the railway business in 1981. Its escalator-manufacturing division was spun off to the company's majority shareholder at the time, Friedrich Krupp AG Hoesch-Krupp, in 1996, leaving the company to focus primarily on construction machines.

O&K expanded to build freight and passenger cars, and above all, excavators for construction. The company also built other heavy equipment, including graders, dump trucks, forklift trucks, compressors, crawler loaders, wheeled loaders, road rollers, and truck cranes. The construction equipment business was sold to New Holland Construction, at the time part of the Fiat Group, in 1999. In 1998, Terex grew its mining business with the acquisition O&K Mining.  In 2009 Terex Sold the mining unit to  Bucyrus International Inc.  At the time products included hydraulic mining excavators and electric drive mining trucks. Then in 2010 Cat bought Bucyrus for $7.6 billion.  The purchase of Bucyrus helped Caterpillar expand its global footprint in the mining equipment industry.