The main mill was steam powered, and above it, a single acting table incline was used to connect to a number of chambers which had been created below the original Pant Mawr workings. The levels were numbered downwards, in a continuation of the numbering scheme adopted by Moelwyn and Pant Mawr, and the mill was on level 18. The building was quite large, and housed at least three saw tables and three dressing machines, although there was room for several more. Beside the mill is a large Lancashire boiler, which was used to store water. A second mill was built near to the exit tunnel in the 1890s, and was designated as level 22. Its purpose may have been to serve lower levels, as the quarry extended down the hillside, or it may have been to process output from the Cefn-y-braich quarry. This consisted of two open terraces, which employed about 20 men between 1877 and 1883. It was subsequently absorbed into the Fron-Boeth operation, and the terraces became levels 19 and 20 in the Fron-Boeth numbering scheme.