The M-class was a class of 17 trams built by Duncan & Fraser, Adelaide for the Hawthorn Tramways Trust (HTT) as numbers 1 to 10, and 33 to 39.

These cars had clerestory roofs, a centrally located passenger saloon (over the wheels) with four windows on each side, and open end platforms for smokers - each with two cross-bench seats, and separated from the drivers cabin by a bulkhead featuring stained glass lead-light panels.

When the Trust ordered seven more to the same design, they specified that more leg room was to be provided in the open drop-end smokers' compartments resulting in those trams being 1 foot (305 mm) longer than the first ten.

After delivery was eventually taken, they then languished in storage at Hawthorn Depot as the electrical equipment to fit them out for service had been delayed due to World War I.

[1][2][3][4][5][6][7] Apart from being renumbered, all trams were repainted in the M&MTB standard brown ("chocolate & cream") livery; when the alphanumeric classification scheme was condensed they joined the other drop-end, open California combination cars as A class.