The lathe tailstock is used to hold the end of the workpiece opposite the drive plate from wobbling. Commonly fitted with a bearing-equipped center point, the lathe tailstock makes it possible to exert pressure against the spinning workpiece without creating an out-of-balance condition. As it is adjustable and able to slide back and forth on the lathe bed, the tailstock can accommodate a wide selection of differing length pieces on the machine. Many lathe owners keep two or more tailstocks on hand, each equipped with a different type of face plate or center point to facilitate differing types of lathe-turning operations. The tailstocks are changed by loosening a single lock and sliding the assembly off of the end of the lathe bed and reversing the process for replacement.
A lathe is used to turn square stock into round stock, among other things. The lathe tailstock is used to support the workpiece and keep it solid and straight in the lathe as it spins at high speed. Without the tailstock, long pieces of stock would simply deflect away when a cutting tool was pushed into it in an attempt to cut or shape it. By locking both ends of the stock between the drive-plate or chuck and the tailstock, the stock remains straight and true even with a great deal of tooling or sanding pressure placed against it.
There are many different styles of center points used in a lathe tailstock, with a live center and a dead center being the two most commonly used. A live center point consists of a steel body containing a bearing-equipped center point that allows the point to spin with the rotating stock. This avoids any burning of the stock and makes for a more stable spin of the workpiece. The dead center point is a steel point that is locked solidly into the tailstock and does not turn. Often, the lathe operator will place a drop of petroleum jelly or other lubricant on the center point to avoid burning the stock while it is turned in the lathe.
When turning a bowl or similar object on a face plate, the lathe tailstock is commonly slid to the end of the lathe's bed and kept out of the way. The tailstock may be used to support the weight of the bowl during the initial shaping and turning stages. Once it is time to hollow the bowl, the tailstock is slid out of the way.