The South African Railways Class 6 4-6-0 of 1893 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

At the end of the Second Boer War in 1902, these ten became the Class 6-L1 on the Central South African Railways.

In 1912, all forty locomotives were renumbered and designated Class 6 when they were assimilated into the South African Railways.

[1][2][3] To meet the increasing weight of fast passenger trains on the Western and Midland Systems, the 6th Class 4-6-0 passenger steam locomotive was conceived and designed at the Salt River works of the Cape Government Railways (CGR) at the same time as the 7th Class, both according to the specifications of Michael Stephens, then Chief Locomotive Superintendent of the CGR, and under the supervision of H.M. Beatty, then Locomotive Superintendent of the Western System.

[1] The boiler had an operating pressure of 160 pounds per square inch (1,103 kilopascals) and was equipped with Ramsbottom safety valves, while the firebox had a brick arch.

They were fast, easy to handle, good steamers and had an exceptionally low maintenance cost, with long periods between major overhauls.

Elliot, General Manager of the CGR at the time, stated in his annual report in 1894 that the increased speed of which they were capable would render practicable the running of passenger trains between Cape Town and Johannesburg in 48 hours.

Hyde, Chief Locomotive Superintendent of the Central South African Railways (CSAR) from 1902 to 1904, considered the 6th Class as "about the best design for their weight ever made".

[3][9] In 1912, these forty locomotives were renumbered in the range from 401 to 440 on the South African Railways (SAR) and designated Class 6.

They were employed on branchlines all over the country, Natal excepted, and practically every big station and several smaller ones had its quota of these handy locomotives to work the local passenger, goods and shunting services.

They were sold to the Sudan Railways Corporation in 1942 and were renumbered in the range from M700 to M706, in the same order as their former SAR engine numbers.

During the 1930s, many of them were modified once again, when the Chief Mechanical Engineer of the SAR at the time, A.G. Watson, embarked on his program of standardisation and reboilered them with round-topped fireboxes once again while retaining the larger cabs.

[1] It would appear that the Western System was more concerned with having unbroken number ranges than the CGR itself was about awarding different classifications to dissimilar locomotives, even if they were of different wheel arrangements.