Lathes are employed for turning external cylindrical, tapered, and contour surfaces, boring cylindrical and tapered holes, machining face surfaces, cutting external and internal threads, knurling, centering, drilling, countersinking, counterboring, spot facing and reaming holes, cutting off, etc. Engine lathes provide a means for feeding the cutting tool along the axis of workpiece revolution. The lathe is one of the machine tools most well used by machining.