How much do you know about milling？

Milling is a cutting process that employs a milling cutter to eliminate material from a workpiece's surface. The milling cutter, which often features multiple cutting edges, rotates to achieve this. Unlike drilling, where the tool advances along its rotational axis, milling involves moving the milling cutter perpendicular to its axis, resulting in cutting occurring around the milling cutter's circumference.

As the milling cutter penetrates the workpiece, its cutting edges repetitively engage and disengage with the material. This action leads to the removal of chips from the workpiece with each pass.

The cutting action involves a shear strain, causing the material to break away from the workpiece in small clusters that form chips. This sets cutting metal apart from cutting softer materials using a blade.

The milling process entails making numerous separate, minor cuts. This can involve using a multi-tooth cutter, rotating it at high speed, or gradually advancing the material through the cutter. Often, a combination of these approaches is utilized.

Adjustments are made to the speeds and feeds to accommodate a range of variables. The speed at which the workpiece progresses through the cutting device is referred to as the feed rate, or simply the feed. It's usually measured as distance per time, although distance per revolution or per cutter tooth is sometimes used as well.

There are two primary categories of milling processes:

Face Milling: Here, the cutting action primarily occurs at the corners of the milling cutter's end. Face milling is employed to create flat surfaces on the workpiece or to generate flat-bottomed cavities.

Peripheral Milling: In this type, the cutting predominantly takes place along the periphery of the milling cutter. As a result, the cross-section of the milled surface mirrors the shape of the milling cutter. The blades of the milling cutter can be likened to the removal of material from the workpiece. Peripheral milling is particularly suited for creating deep grooves, threads, and gear teeth.