4-6-0 passenger locomotives became quite popular in Russia at the turn of the 20th century.
While the locomotives originally had separate class designations on each Russian railroad, common Russian class designations were introduced in 1912.
The Russian 4-6-0s were the A, AᴰK, Aᴰ, Aⱽ, V, Zh, Z, G, U, K, B and Kᵁ classes.

The first and most numerous class was the Vladicaucasian Railway's A class, in the AᴰK, Aᴰ and, the most numerous, Aⱽ series.
It was a Kolomna factory design, of which 533 were built for several railroads in several Russian and German factories from 1892 until 1907.
All were two-cylinder compound locomotives with 1,830-millimetre (72-inch) diameter coupled wheels.

In 1896, 88 Baldwin-built four-cylinder Vauclain compound locomotives were introduced, designated V class (V for Vauclain, В in Russian).

Also from 1896, Henschel-designed locomotives were introduced.
Altogether 210 were built from 1896 to 1909, fourteen by Henschel and the rest in Russia.
They were two-cylinder compound locomotives with 1,700-millimetre (66.93-inch) diameter coupled wheels and were regarded as a more successful design than the A class.
These locomotives were later designated as the Zh class (Ж in Russian).
A development of the  Zh class was the superheated Z class (З in Russian), of which 24 were built from 1902.

From 1901 to 1903, stronger passenger locomotives were built, the G class (Г in Russian).
These locomotives were of Vladicaucasian Railway and Bryansk factory design.
Of these, 39 were built for the Vladicaucasian Railway and another 85 for Eastern Chinese railroads.
They were two-cylinder compound locomotives with 1,730-millimetre (68.11-inch) diameter coupled wheels.
Some of these locomotives were later retrofitted with superheaters.

The class U (У in Russian) was a four-cylinder oil burning De Glehn compound locomotive which first appeared in 1906, initially on the Ryazan-Ural railroad.
Of these, 62 were built at the Kirov Plant between 1906 and 1916.
By the beginning of 1940, the inventory still listed 47 U class locomotives and the last of them were withdrawn in 1952.
Lenin's locomotive, U class no.
U-127 that was used during his funeral, is preserved at the Museum of the Moscow Railway.

Altogether 145 heavier superheated K class (К in Russian) passenger locomotives were built between 1907 and 1912.
They were of Kolomna factory design and were two-cylinder simple expansion (simplex) locomotives with 1,700-millimetre (66.93-inch) diameter coupled wheels.

At the same time, the Briansk factory designed an improved superheated development of the G class that was produced between 1907 and 1914 as the B class (Б in Russian).
Altogether 252 were built in Briansk and Lugansk.
They were two-cylinder simplex locomotives with 1,830 millimetres (72 inches) diameter coupled wheels that were quite successful in express work.

Between 1911 and 1914, Kolomna built 39 stronger Kᵁ class locomotives (КУ in Russian) with 1,900 millimetres (75 inches) diameter coupled wheels for faster trains.
4-6-0 passenger locomotives became quite popular in Russia at the turn of the 20th century. While the locomotives originally had separate class designations on each Russian railroad, common Russian class designations were introduced in 1912. The Russian 4-6-0s were the A, AᴰK, Aᴰ, Aⱽ, V, Zh, Z, G, U, K, B and Kᵁ classes.
The first and most numerous class was the Vladicaucasian Railway's A class, in the AᴰK, Aᴰ and, the most numerous, Aⱽ series. It was a Kolomna factory design, of which 533 were built for several railroads in several Russian and German factories from 1892 until 1907. All were two-cylinder compound locomotives with 1,830-millimetre (72-inch) diameter coupled wheels.
In 1896, 88 Baldwin-built four-cylinder Vauclain compound locomotives were introduced, designated V class (V for Vauclain, В in Russian).
Also from 1896, Henschel-designed locomotives were introduced. Altogether 210 were built from 1896 to 1909, fourteen by Henschel and the rest in Russia. They were two-cylinder compound locomotives with 1,700-millimetre (66.93-inch) diameter coupled wheels and were regarded as a more successful design than the A class. These locomotives were later designated as the Zh class (Ж in Russian). A development of the  Zh class was the superheated Z class (З in Russian), of which 24 were built from 1902.
From 1901 to 1903, stronger passenger locomotives were built, the G class (Г in Russian). These locomotives were of Vladicaucasian Railway and Bryansk factory design. Of these, 39 were built for the Vladicaucasian Railway and another 85 for Eastern Chinese railroads. They were two-cylinder compound locomotives with 1,730-millimetre (68.11-inch) diameter coupled wheels. Some of these locomotives were later retrofitted with superheaters.
The class U (У in Russian) was a four-cylinder oil burning De Glehn compound locomotive which first appeared in 1906, initially on the Ryazan-Ural railroad. Of these, 62 were built at the Kirov Plant between 1906 and 1916. By the beginning of 1940, the inventory still listed 47 U class locomotives and the last of them were withdrawn in 1952. Lenin's locomotive, U class no. U-127 that was used during his funeral, is preserved at the Museum of the Moscow Railway.
Altogether 145 heavier superheated K class (К in Russian) passenger locomotives were built between 1907 and 1912. They were of Kolomna factory design and were two-cylinder simple expansion (simplex) locomotives with 1,700-millimetre (66.93-inch) diameter coupled wheels.
At the same time, the Briansk factory designed an improved superheated development of the G class that was produced between 1907 and 1914 as the B class (Б in Russian). Altogether 252 were built in Briansk and Lugansk. They were two-cylinder simplex locomotives with 1,830 millimetres (72 inches) diameter coupled wheels that were quite successful in express work.
Between 1911 and 1914, Kolomna built 39 stronger Kᵁ class locomotives (КУ in Russian) with 1,900 millimetres (75 inches) diameter coupled wheels for faster trains.
4-6-0