Comparing: IS-6 vs. 110

Plans for this vehicle were drawn up in the construction bureau of the Chelyabinsk Kirov plant from December 1943 to the summer of 1944. Further development and the construction of the first prototype took place at the Uralmash plant. However, the vehicle had no advantages over the other heavy tank designs under consideration, and its armor was seen as inferior to the IS-4 (Object 701), so the IS-6 was not selected for production.

From the mid-1940s to the 1950s, Soviet engineers attempted to modernize the IS-2 tank. The IS-2U variant, developed in November 1944, was conceived to have a reinforced frontal hull with a plate configuration resembling that of the IS-3. In the mid-1950s the design project was passed to China and became the basis of further Chinese tank development.