Stephenson Clarke were one of the largest coal factoring companies in the UK, supplying many types of coal sourced from from British collieries to any destination required. The large volumes of coal being moved made the higher capacity 20-ton steel wagons especially attractive to the company, particularly when combined with the reduced rates charged by the railway companies and lease-hire scheme offered by the GWR who were actively promoting the use of these 20-ton wagons.

Stephenson Clarke had adopted this simplfied lettering scheme, with just the letters S C appearing on the side of the wagons. This helped keep costs down in the hard economic times of the 1930s.