Boring mills are machine tools that can enlarge or finish existing holes on metalworking materials. They can also perform other operations, such as drilling, grinding and contouring. Boring mills can be classified into vertical and horizontal types, depending on the orientation of the spindle. Vertical boring mills are similar to vertical lathes, but have a stationary workpiece and a rotating cutting tool. Horizontal boring mills have a horizontal spindle and a movable workpiece table. Boring mills are widely used in various industries, such as aerospace, defense, energy and construction. They offer high precision, rigidity and productivity for large part machining.