In ordinary turning,metal is removed trom a rotating workpiece with a single-point tool. The tool must be harder than the workpiece and held rigidly against it. Chips formef from the workpiece slide across the face of the tool. This essentially is the way chips are produced in all metal cutting operations. The pressures used in metal cutting can be as much as 20tons per square inch. Tool geometry,therafore,is quite important to maintaim the strength at the cutting edge of the tool bit. Inthis section you will learn how to use common lathes, how to grinď high-speed tools, and how to select tools for lathe work.