Abstract: A plane constructed shaft system used to replace the cylindrical shaft in precision polishing apparatuses. Thus, the accuracy, productivity and cost of polishing apparatuses are improved. The shaft system has a four-surface hollow prism bushing and a four-surface prism shaft that can slide freely within the bushing. The polishing pressure is maintained by the weights of the shaft plus the parts attached to the shaft, but this pressure can be reduced by adjusting a load adjusting nut which compresses a loading spring acting on a collar stop attached to the shaft. The actual polishing pressure can be calculated according to the position of the load adjusting nut. Furthermore, the stock removal amount can be controlled by a stock removal stop ring which is mounted on the collar stop and can be adjusted up and down as required.