History and Terminology of Machining
– The term ‘machining’ has evolved over time.
– In the 18th century, a machinist referred to someone who built or repaired machines.
– Traditional machining processes included turning, boring, drilling, milling, broaching, and more.
– New technologies such as electrical discharge machining and ultrasonic machining have emerged.
– The term ‘subtractive manufacturing’ is sometimes used as a retronym to differentiate from additive manufacturing.

Overview and Categorization of Machining
– Machining is a process where a cutting tool removes material from the workpiece.
– Relative motion is required between the tool and the workpiece.
– Traditional machining uses cutting tools to achieve desired shapes.
– Non-traditional machining processes use alternative methods of material removal.
– Cutting speed and feed are important factors in machining operations.

Traditional Machining Operations
– Traditional operations include turning, boring, drilling, reaming, threading, milling, broaching, sawing, grinding, and shaping.
– Circular and straight shapes are machined differently.
– The shape of the cutting tool and its penetration into the workpiece determine the resulting work surface.

Cutting Tools
– A cutting tool has sharp cutting edges and is made of a harder material than the work material.
– The rake face directs the flow of the chip and has a rake angle.
– The flank provides clearance and has a relief angle.
– Single-point tools are used for turning, boring, and planning.
– Multiple-cutting-edge tools have more than one cutting edge and are used for drilling and milling.

Non-Traditional Machining Techniques
– Non-traditional machining techniques include plasma beam machining, waterjet machining, and electrical discharge machining (EDM).
– Advanced CNC machines can combine lathe and milling operations.
– Non-traditional machining techniques like EDM can achieve small kerf and intricate shapes.
– Non-traditional machining techniques like EDM can machine holes or cut out specific shapes.Sources: