Boring

Boring is usually performed when a hole with a large diameter is needed. This method is especially common when a component is big or if its shape makes it difficult mount the piece in other machine tools. Boring is carried out in a boring machine, sometimes refered to as a horizontal boring machine or drilling and milling machine. Also, there are several different kinds of boring machines tools, such as the drum-type boring machine. Common for all boring machines are that they operate horizontally. 

A boring machine tool is usually capable of drilling, cutting and sometimes even turning too. Usually the depth, width and height of the component determine which boring machine is suitable for a specific component. 
Compare horizontal boring to vertical boring, where the bore appoaches the component from above.