Hanomag was a German producer of steam locomotives, tractors, trucks and military vehicles in Hanover. Hanomag first achieved international fame by delivering numerous steam locomotives to Finland, Romania and Bulgaria before World War I and making of first tractor Hanomag R26 in 1924 in Germany. In 1925, they added automobiles to their line, additionally moving in 1931 into the production of construction machinery. Since 1989, the company has been part of the Komatsu company.
In 1912 Hanomag started the production of plows with up to 80 hp benzene engines. In 1924, the first farm tractor WD 26 (WD) with a 26 hp four-cylinder benzene engine was presented to the market. In 1931, the first diesel tractor RD 36 with a 36-horsepower four-cylinder engine, and 5.2 liters of capacity was made. Hanomag was the market leader in 1939 and the early 1950s. In 1951, a series of new tractors were developed, based on a modular system with 2-,3-, and 4-cylinder engines. From 1962 until the cessation of production in 1971, only four-stroke diesel tractors were built.
From 1912 to 1971, more than 250,000 machines from 12 to 92 hp left the factory halls in Linden. In addition, there were manufacturing facilities in Argentina and license agreements with Spanish industrialists.
During World War II, the car plant made military vehicle engines, a military version of their heavy tractor renamed the SS-100, and half track troop carriers. The Hanomag 20 B, a four-wheel-drive Small Unit-Personnel Carrier was produced from 1937 until 1940 (circa 2000 built) under the parentage of Stoewer (as the R180, R200 and Type 40). Capacity problems by Stoewer resulted in co-production by both BMW (as the 325) and Hanomag. Together, the three manufacturers made about 10,000 units. The special four-wheel-steering system was fitted on most models. Operating a "lock-level" between the front seats, made the steerable rear axle turn sideways to a certain angle.
The single most important and iconic military vehicle to be designed and built by Hanomag during World War II was the Sd.Kfz. 251 half-track (commonly called simply "the Hanomag") with a total production numbering just over 15,000. Built to protect and transport the Panzergrenadier mechanized infantry forces, it was by far the most common German armoured troop-carrying vehicle of World War II, and a direct precursor to the armoured personnel carriers of today. In comparison to the most common Allied half-track of the war, the M3 Half-track, the Sd.Kfz. 251 was slower and lower-powered, but with thicker, sloping side armour provided better protection; the flat-sided M3 was, at one point, panned as the "Purple Heart Box" for being unable to stop 7.92mm Mauser bullets at close range, while the Hanomag's sloping side armour deflected Allied bullets with no similar issue.
Post-war production resumed, making trailer units, followed by tractors and, in 1949, a 1.5 ton truck. Although prototypes were made, no cars were produced postwar. Rudolph Hiller, who had been president of Phänomen trucks, joined the board and restructured the company by arranging for it to join the Rheinstahl consortium in 1952.