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Table 3.1 Machining processes

Process Description Image
Turning The turning process is a machining operation used to remove material from a rotating workpiece to create a cylindrical shape. It is one of the most
fundamental and widely used metal cutting processes in manufacturing industries. The primary machine used for turning is called a lathe.
In the turning process, the workpiece is clamped onto the lathe and rotated about its axis. A single-point cutting tool is then fed into the rotating
workpiece, and the excess material is removed in the form of chips, leaving behind a cylindrical surface with the desired dimensions and finish.
Here are the key steps involved in the turning process:
• Workpiece Setup: The workpiece, typically a cylindrical or rod-shaped material, is mounted between the lathe's headstock and tailstock or in
a chuck, which holds it securely in place for rotation.
• Tool Selection: The cutting tool, usually made of high-speed steel or carbide, is selected based on the material being turned and the desired
surface finish. (Source of image:
• Tool Positioning: The cutting tool is positioned at the correct height and angle relative to the rotating workpiece to achieve the desired cutting https://www.rapiddirect.com/blog/types-of-
action. machining-operations/)
• Cutting Operation: The lathe's spindle rotates the workpiece, while the cutting tool is fed into the material. The tool removes material in the
form of chips as it moves along the workpiece's length.
• Feed and Depth of Cut: The feed rate (the distance the tool advances into the workpiece per revolution) and the depth of cut (the thickness
of the material removed in a single pass) are carefully controlled to achieve the desired dimensions and surface finish.
• Coolant/Lubricant: During the turning process, cutting generates heat. To prevent overheating and maintain the tool's efficiency, coolant or
lubricant may be used to cool and lubricate the cutting zone.
The turning process can be used to create various cylindrical shapes, including external diameters, internal bores, tapers, threads, and chamfers. It
is employed in a wide range of industries, including aerospace, automotive, machinery, and general manufacturing.
In addition to traditional turning, there are specialized turning processes like facing, boring, grooving, and threading, which focus on specific features
or operations to achieve the desired final product. Turning is valued for its versatility, efficiency, and ability to produce accurate and smooth
cylindrical shapes at a relatively low cost compared to other machining processes.
Milling Milling is a machining process that involves using rotary cutters to remove material from a workpiece, creating complex shapes, profiles, and
features. It is one of the most versatile and widely used machining operations in manufacturing and fabrication industries.
The milling process typically involves the following steps:
• Workpiece Setup: The workpiece is securely clamped to the milling machine's worktable or fixture, ensuring it remains stationary during the
milling operation.
• Milling Cutter Selection: The appropriate milling cutter (also known as an end mill) is chosen based on factors such as the material of the
workpiece, the desired shape, and the required surface finish. Milling cutters come in various types, including end mills, face mills, ball nose
cutters, and more.
• Tool Positioning and Alignment: The milling machine's spindle holds the selected milling cutter, which is positioned and aligned accurately
with the workpiece to achieve the desired machining path. (Source of image:
• Milling Operation: As the milling machine's spindle rotates the cutter at high speed, the cutter's teeth engage with the workpiece and remove https://www.rapiddirect.com/blog/types-of-
machining-operations/)
material, creating chips. The workpiece may remain stationary, or the milling machine's table may move the workpiece in relation to the
rotating cutter to achieve the desired shapes and features.
• Coolant/Lubrication: During the milling process, heat is generated due to the cutting action. To prevent overheating and extend tool life,
coolant or lubricant may be used to cool and lubricate the cutting zone.

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