WHAT IS TURNED, GROUND AND POLISHED?
Metal shafts used in high-speed applications require a large amount of precision. If the shafts have rough finishes or lack concentricity and straightness, premature wearing of either the shaft or bearing being used can occur. In order to achieve the high level of precision required, steel shaft manufacturers often use a process called turned, ground and polished. This process involves – as the name implies – three important steps that converts a coarse, roughly dimensioned metal rod to a shaft with a straight and smooth finish. Turned: First, oversized steel rods are placed into a lathe chuck and tightened, and a cutting tool is placed in the tool holder on the lathe. The lathe is then started and the rod begins to spin. Once the steel rod reaches the desired speed, the cutting tool is fed into the rod which begins the process. The turning continues until the steel rod is brought down to the desired size. Multiple passes may have to be made with the cutting tool depending on h...