Mechanical hammers have been known of and used since the ancient period. Same with sawmills. There are even examples of the romans using sawmills to cut stone (I'm guessing it was sandstone or something, not granite =P). Their existence in your town is going to be down to various factors but if there is running water present, I'm sure they'd make use of it. And the sheer quantity of wood required in building and maintaining that city would make sawmills very valuable unless there is a significant amount of cheap labour available (like slaves).