Grosstraktor (German: "large tractor") was the codename given to six prototype medium tanks built (two each) by Rheinmetall-Borsig, Krupp, and Daimler-Benz, for the Weimar Republic, in violation of the Treaty of Versailles.

Constructed in secret, they were tested by Reichswehr units at the Kama tank school in the Soviet Union.

Contracts to design and build two chassis in soft steel were given to Daimler-Benz, Krupp, and Rheinmetall in March 1927.

[2] Construction of the six Grosstraktor was started at a Rheinmetall shop in Unterlüß in August 1928, and was completed by the end of June 1929.

They were then shipped to a secret testing ground near Kazan, Russia for trials, arriving in July 1929.