In 1941 Stalin took a gamble and moved his main T-34 plant in Kharkov to Nizhni Tagil in the Ural Mountains, effectively halting tank development while the new factory was set up and other plants were brought online. The focus on tank development was temporary taken off development and concentrated on making the T-34 quicker and easier to build.
The T-34 obr 1941 (late) is the result of simplifying the construction of the T-34, from the comparatively complex construction of the 1940 and 41 models.     

Like the 1941 model the later version was armed with the F-34 76.2mm gun, and had a welded or cast single hatch turret. It did start to take on a few features that are seen in the later obr 1942 and 85mm models like the armoured hull machine gun cover and the PTK-5 periscope.

T-34 obr 1941, Late Version

Produced by Factory No.100 at Chelyabinsk (ChKZ)

The Urals became a centre of tank production after the evacuation of the Kharkov, and parts of the Leningrad, production, and later from Stalingrad. The new tank factories were set up to take advantage of a vast tractor works built in the 1930s during collectivisation.
Equipment from the tank factory at Kirov was merged with that from Leningrad. The Ural-Kirov Tank Factory in Chelyabinsk was set-up by the People’s Commissariat for the Tank Industry to produce T-34s.

The Kharkov Locomotive Factory were moved to the Uralmashzavod (Ural Machine Building Plant) in the Urals and merged with the Nishni Tagil auto factory. The whole complex of factories around Chelybinsk became known later as Tankograd.

One of the pieces of equipment inherited from the existing industry was a huge 5,000-ton forge-press. So rather than cast or weld the new 1942 model hexagonal T-34 turret, the Chelyabinsk factory (ChKZ) simply stamped them out from the heated metal plate.    
    
Some pressed Turrets were also used on T-34s from the Uralmash Factory at Nishni Tagil. A total 2670 of these dropforged turrets were made.