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Broaching Broaching is a machining process used to remove material from a workpiece quickly and accurately to create internal or external features with a
high level of precision. It is a highly productive process, especially for producing keyways, splines, gears, and other complex shapes that would be
challenging or time-consuming to create using other methods.
The broaching process involves a specialized tool called a broach, which is a multi-toothed cutting tool. The broach has a series of teeth, each with
a slightly larger cutting edge than the previous one. The broach is pulled or pushed through the workpiece, and as it advances, each tooth
successively removes a small amount of material, gradually forming the desired shape.
There are two main types of broaching:
• Internal Broaching: In internal broaching, the broach is used to cut internal features within a workpiece, such as keyways inside a bore or hole.
• External Broaching: In external broaching, the broach is used to cut external features on the surface of a workpiece, such as splines or gears
on a shaft.
• The broaching process can be done using different methods:
• Surface Broaching: In this method, the broach is moved linearly across the workpiece's surface to create external features.
• Pull Broaching: In pull broaching, the broach is pulled through the workpiece from one end to the other to create internal features.
• Push Broaching: In push broaching, the broach is pushed through the workpiece from one end to the other to create internal features.
Broaching offers several advantages: (Source of image:
• High accuracy and repeatability in producing complex shapes. https://www.rapiddirect.com/blog/types-of-
machining-operations/)
• Faster material removal compared to many other machining processes.
• Single-pass operation, which reduces machining time and costs.
• Suitable for mass production due to its efficiency.
However, broaching also has some limitations, such as being suitable only for certain shapes and sizes, requiring specialized machines, and being
more challenging for materials with high hardness or toughness.
Overall, broaching is a valuable machining process used in various industries, including automotive, aerospace, and manufacturing, where high-
precision and productivity are essential for creating intricate shapes and features.
Planing The planing process is a machining operation used to create flat surfaces on large workpieces. It is a linear motion cutting process, where the cutting
tool removes material in a reciprocating motion to achieve the desired surface finish and dimensions. Planing is typically used for workpieces that
are too large to be effectively machined on milling machines.
The key features and steps involved in the planing process are:
• Workpiece Setup: The workpiece is firmly fixed to a horizontal bed or table of a planer machine. The bed may also have additional lateral and
longitudinal movements to position the workpiece accurately.
• Cutting Tool: The cutting tool used in planing is called a planer tool or planer bit. It is a single-point cutting tool with a large cutting edge. The
tool is mounted on a reciprocating mechanism, allowing it to move back and forth across the workpiece.
• Cutting Operation: During the planing process, the workpiece remains stationary on the table, while the planer tool moves back and forth in
a linear motion over the workpiece. As the tool moves forward, it cuts into the workpiece, removing material and creating a flat surface. On
the return stroke, the tool lifts slightly above the workpiece to avoid cutting. (Source of image:
• Feed Rate and Depth of Cut: The feed rate and depth of cut are controlled to determine the rate of material removal and the surface finish https://www.rapiddirect.com/blog/types-of-
machining-operations/)
achieved. The cutting parameters are carefully set to avoid excessive cutting forces and to ensure a smooth finish.
• Cooling and Lubrication: Similar to other machining processes, planing generates heat at the cutting zone. To prevent overheating and prolong
the tool's life, coolant or lubricant is often applied during the process.

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