One of the locomotives which achieved the highest numbers in the Hungarian State Railways was the series IIIq 0-6-0 freight locomotive. It was considered the successor to the IIIe, but in contrast to this had an internal frame. Between 1893 and 1907, MÁV received 247, all of which were manufactured by MÁVAG. The KsOd also purchased 35 identical machines that were delivered between 1899 and 1909 and were also referred to as IIIq. At the MÁV they became the class 325 from 1911.

It was powered by a two-cylinder compound engine. To adapt to different requirements, a blastpipe with a variable cross-section was installed, with which the balance between the counter pressure of the cylinders and the draft could be changed. Due to its excessive complexity, this mechanism was later removed again.

Despite the overhanging cylinders and firebox and the resulting poorer running smoothness, these locomotives were also regularly used to transport passenger trains. After the First World War, 102 had to be given to Romania, 68 to Yugoslavia, nine to Czechoslovakia and three to Poland.