The stone floor of De Valk consists of one pair of mill stones. These are made in a millstone factory. One pair of mill stones consists of a bedstone and a runner stone. The grain is falling between the stones by means of a hole in the middle of the runner stone. In the first part, the grain is distributed. In the second part, the grain is broken and in the third part, the grain is crushed. After that the flour is falling down to the meal floor.
Sharpening the stones is called "billen" of the stone. When the stones are sharpened, the upper stone needs to be pulled up by means of a crane. The stone weights about 1200 kg. Sharpening the stones takes a very long time. The miller has to do it very accurate.