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It’s necessary to know the 8 common CNC machining techniques if we need to learn about their applications, advantages, and key features. In this article, we are going to explore the essential CNC machining techniques including turning, milling, drilling, grinding, boring, planing, broaching, and electrical discharge machining (EDM).
It’s very important to investigate how a product is processed if we hope to survey its cost structure. Learning the 8 common CNC machining techniques will help you a lot.
When it comes to the manufacturing industry, mechanical machining processes are an essential part. Mechanical machining is the process of transforming raw materials into the desired shape, size, and surface quality, covering a variety of precision machining methods to meet the needs of different parts. Below, we will detail 8 common mechanical machining techniques.
You can also choose to directly explore Bole’s CNC Machining service if you are a master in this field.
Turning
Turning involves fixing the workpiece on a rotating workpiece holding device and then gradually cutting the material on the workpiece using a cutting tool to obtain the desired shape and size. This method is suitable for manufacturing cylindrical parts such as shafts and sleeves. The turning method and tool selection influence the final product’s shape and surface roughness.
Turning can be divided into different types, including external turning, internal turning, facing, and threading.
External turning is commonly used for machining shapes like shafts, cylinders, and cones; in internal turning, the tool enters the workpiece’s inner hole to process the diameter and surface to the required size and accuracy; facing is typically used to create flat surfaces, such as the base or end face of a part; threading is achieved by gradually cutting the thread shape by moving the cutting edge of the tool relative to the workpiece’s surface, including internal and external threads.
Milling
Milling involves rotating a cutting tool on the workpiece surface to cut material, allowing for the production of parts with complex shapes such as planes, concave and convex surfaces, and gears by controlling the tool’s movement. Milling includes flat milling, vertical milling, end milling, gear milling, and profile milling, each suitable for different machining needs.
In flat milling, the cutting edge of the tool cuts on the workpiece surface to achieve a flat surface; vertical milling is used for machining grooves and holes along the height direction of the workpiece; end milling involves cutting on the side of the workpiece and is used for machining profiles, grooves, and edges; gear milling typically uses special tools with cutting edges to cut the gear teeth shape; profile milling is used for processing complex curves or contour shapes, with the tool path precisely controlled based on the contour.
Drilling
Drilling involves cutting material on the workpiece using a rotating drill bit to create holes of the desired diameter and depth, widely used in manufacturing, construction, and maintenance fields. Drilling is often categorized into conventional drilling, center drilling, deep hole drilling, multi-axis drilling, among other types.
Conventional drilling uses drill bits with spiral cutting edges, typically for smaller holes and general drilling needs; center drilling involves creating a small hole on the workpiece surface before using a larger drill bit to ensure the accurate positioning of larger holes; deep hole drilling is used for processing deeper holes, requiring special drill bits and cooling techniques to ensure accuracy and quality; multi-axis drilling uses multiple drill bits at different angles simultaneously, suitable for cases where multiple holes need to be drilled simultaneously.
Drilling is a very regular processing method as one of the common CNC machining techniques.
Grinding
Grinding involves gradually cutting or grinding material on the workpiece surface using an abrasive to obtain the desired shape, size, and surface quality. Grinding is commonly used for parts with high precision and surface quality requirements, such as molds, precision mechanical parts, and tools.
Grinding is divided into flat grinding, external grinding, internal grinding, and profile grinding. Flat grinding is used for processing flat workpiece surfaces to achieve smooth surfaces and precise dimensions; external grinding is used for processing the outer cylindrical surface of workpieces such as shafts and pins; internal grinding is used to process the inner surface of holes, such as inner holes and shaft holes; profile grinding is used for processing complex contour shapes, such as the cutting edge of molds and tools.
Boring
Boring is used to process internal circular holes in workpieces by cutting in existing holes with a rotating tool to achieve precise dimensions and flatness goals. Unlike drilling, where holes are formed by cutting material on the workpiece surface, boring involves inserting the tool into the workpiece to cut holes.
Boring is divided into manual boring and CNC boring. Manual boring is suitable for small-batch production and simple machining tasks; CNC boring uses programming to determine cutting paths, feed rates, and rotation speeds to achieve automated high-precision machining.
Planing
Planing involves cutting material on the workpiece surface using a planer to achieve the desired flat surface, precise dimensions, and surface quality. Planing is commonly used for machining flat surfaces of larger workpieces, such as bases and beds. It provides a flat surface for workpieces to fit with other components.
Planing is typically divided into roughing and finishing stages. In the roughing stage, the planer cuts deeply to quickly remove material. In the finishing stage, the cutting depth is reduced to achieve higher surface quality and dimensional accuracy. Planing can be manual or automatic. Manual planing is suitable for small-batch production and simple machining tasks; automatic planing uses automated machine tools to control the movement of the planer for a more stable and efficient machining process.
Broaching
Broaching involves gradually deepening cuts using a broaching tool to create internal complex contours, commonly used for machining the contours, grooves, and holes of workpieces with complex shapes. Broaching can achieve high machining accuracy and surface quality, suitable for parts requiring high precision and good surface quality. It is generally categorized into flat broaching, contour broaching, groove broaching, and hole broaching.
Flat broaching is used for machining flat workpiece surfaces to achieve smooth surfaces and precise dimensions; contour broaching is used for processing complex contour shapes, such as molds and parts; groove broaching is used for machining grooves and slots, with the cutting edge entering the workpiece and cutting along the workpiece surface; hole broaching is used for machining the inner contour of holes, where the cutting edge enters the hole and cuts the inner surface of the hole.
Electrical Discharge Machining (EDM)
EDM uses electrical discharge to cut and process conductive materials, creating high-precision, complex-shaped parts such as molds and tools. It is commonly used in the manufacturing of molds, plastic injection molds, aerospace engine parts, medical equipment, and other fields. EDM is suitable for cutting hard, brittle, or high-hardness materials that are difficult to cut using traditional machining methods, such as tool steel, hard alloys, and titanium alloys.
Key Features of Electrical Discharge Machining:
EDM has a very high technique level in the 8 common CNC machining techniques.
Non-contact cutting: Unlike traditional mechanical cutting, EDM is a non-contact machining method. There is no direct physical contact between the tool and the workpiece; material is removed through electrical discharge.
High precision: EDM can achieve high-precision machining, often reaching sub-micron level dimensional accuracy. This makes it suitable for manufacturing molds, models, and other precision parts.
Complex shapes: As EDM is a non-contact machining method, it can be used to process very complex shapes, including internal contours, small holes, slots, and more.
Suitable for high-hardness materials: EDM is suitable for high-hardness materials since it does not rely on the hardness of cutting tools in traditional cutting methods.
Conclusion:
Mastering the 8 common CNC machining techniques is essential for precision manufacturing. Each one has its specific applications and advantages. By understanding the applications and advantages of turning, milling, drilling, grinding, boring, planing, broaching, and EDM, manufacturers can optimize their machining processes for superior results. We can choose the right technique according to the material, shape, size, and surface requirements of the part.
