What is Milling: Definition, Process & Operations
Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece. This may be done in varying directions on one or several axes, cutter head speed, and pressure. Milling covers a wide variety of different operations and machines, on scales from small individual parts to large, heavy-duty gang milling operations.
Milling Definition
Milling is a cutting process where we use a cutter to remove the material from the surface of a metal or workpiece. This cutter which we use has multiple rotating cutting surfaces. Milling cutters play an important role in the milling process and they are used in several milling machines. Milling cutters are of many sizes and shapes. Following is the list of cutters of different shapes.
- End mill.
- Side and face mill.
- Roughing end mill.
- Ball nose cutter.
- Slab mill.
Milling can be done with a wide range of machine tools. The original class of machine tools for milling was the milling machine (often called a mill). After the advent of computer numerical control (CNC), milling machines evolved into machining centers (milling machines with automatic tool changers, tool magazines or carousels, CNC control, coolant systems, and enclosures). Today, CNC mills with automatic tool change and 4- or 5-axis control obviate gang-milling practice to some extent.
Milling Process
The milling process requires a milling machine, workpiece, fixture, and cutter. The workpiece is a piece of pre-shaped material that is secured to the fixture, which itself is attached to a platform inside the milling machine. The cutter is a cutting tool with sharp teeth that is also secured in the milling machine and rotates at high speeds. By feeding the workpiece into the rotating cutter, the material is cut away from this workpiece in the form of small chips to create the desired shape.
Milling operations can also be added to a lathe’s capabilities and really expand the types of workpieces machinable on a single machine. For example, a fly cutter is formed by mounting a standard milling cutter in a lathe dog or a special quick-change tool post.
Milling Operations
The common milling operations include:
- Face Milling
- Peripheral Milling
- Plunge Milling
- Profile Milling
- Slot Milling
- Straddle Milling
- Angular Milling
- Form Milling
These milling operations are used to produce various types of parts in different shapes and sizes. Milling is typically used to produce parts that are not axially symmetric and have many features, such as holes, slots, pockets, and even three-dimensional surface contours.
Milling Machines
Modern milling machines come in many different varieties. The two basic configurations are vertical and horizontal. Both types vary in size and complexity. Vertical milling machines are generally more suited to larger jobs, while horizontal milling machines are used for smaller jobs. The most common type of milling machine is a CNC milling machine, which is controlled using a computer. These machines can range from small tabletop models to full-size industrial milling machines.
Milling machines can be used in both horizontal and vertical orientations, and many can perform multi-axis machining. The cutting heads can move in a variety of directions, and can often move in multiple planes at once. This makes milling machines ideal for creating complex shapes and forms.
Conclusion
Milling is a versatile process widely used in industrial manufacturing. It is used to produce parts of different shapes and sizes with high accuracy. The process involves the use of a milling machine, a workpiece, and a cutter. There are various types of milling operations used for different applications. The most common type of milling machine is the CNC milling machine, which is computer-controlled for maximum precision.