A grinding machine comprising a tool mounting head which is movable vertically between a pair of guide columns on which guide surfaces are provided for guiding the head. A plurality of workpieces are mounted on corresponding holding jigs which are mounted by means enabling them to be tilted, and measurement means such as X-ray or optical means are provided to sense the orientation of a workpiece being machined, with signals from the measurement means controlling the tilting of the corresponding holding jig. Jigs are mounted on a rotary table rotatably mounted on a workpiece slide which can be traversed below a grinding tool.
