5.4 Basic Machine Tool Operations

1. Turning

Turning is a machining process where a cutting tool is used to remove material from a rotating workpiece. This operation is commonly performed on a lathe, which allows for the creation of cylindrical shapes. The cutting tool is fed into the workpiece at a controlled depth and speed to achieve the desired shape and dimensions.

Example: When machining a cylindrical shaft, the lathe is set to rotate the shaft at a specific speed. The cutting tool is then fed into the shaft, removing material to create a smooth, cylindrical surface. This process can also be used to create threads, grooves, and other features on the shaft.

2. Milling

Milling is a machining process where a rotating multi-point cutting tool is used to remove material from a stationary workpiece. Milling machines can perform a variety of operations, including cutting slots, pockets, and complex shapes. The workpiece is typically moved against the rotating cutting tool to achieve the desired shape.

Example: When machining a flat plate with a slot, the milling machine is set to rotate the cutting tool at a high speed. The workpiece is then moved against the tool, removing material to create the slot. Milling can also be used to create intricate patterns and features on the surface of the workpiece.

3. Drilling

Drilling is a machining process where a rotating cutting tool with a pointed end is used to create a hole in a workpiece. Drilling is typically performed on a drill press, which allows for precise control of the cutting tool's depth and speed. The cutting tool is fed into the workpiece to create a hole of the desired diameter and depth.

Example: When machining a metal plate with a hole, the drill press is set to rotate the drill bit at a specific speed. The drill bit is then fed into the plate, removing material to create a hole. Drilling can also be used to create countersinks, counterbores, and other types of holes.

4. Grinding

Grinding is a machining process where a rotating abrasive wheel is used to remove material from a workpiece. Grinding is typically used for finishing operations, where a high degree of surface finish and dimensional accuracy is required. The workpiece is moved against the rotating grinding wheel to remove material and achieve the desired surface finish.

Example: When machining a hardened steel part, grinding is used to achieve a smooth, polished surface. The grinding wheel is set to rotate at a high speed, and the workpiece is moved against the wheel to remove material and create a smooth surface. Grinding can also be used to sharpen tools and create precise shapes on the workpiece.

5. Sawing

Sawing is a machining process where a cutting tool with teeth is used to cut a workpiece into separate pieces or to create specific shapes. Sawing is typically performed on a bandsaw or a circular saw, which allows for precise control of the cutting tool's speed and depth. The cutting tool is fed into the workpiece to create the desired cut.

Example: When machining a large metal bar into smaller pieces, a bandsaw is used to cut the bar into individual pieces. The bandsaw is set to rotate the cutting blade at a specific speed, and the bar is fed against the blade to create the cuts. Sawing can also be used to create specific shapes and profiles on the workpiece.