CNC milling is one type of computer numerical controlled machining process which is quite similar to cutting and drilling. In CNC milling machines the cutter can move in multiple axes for creating different shapes, holes and slots. Additionally, the material is moved in multiple directions across the tool to achieve desired shape, which is an improvement over a drill’s single axis motion.

In the following sections we will look at several different details about CNC milling such as:

  • How CNC milling machines are categorized?
  • What is the benefit of using CNC milling?
  • What are the basic elements of CNC milling?
  • What are the different categories of CNC milling procedure?
  • Type of mills which can be used


How CNC Milling machines are categorized?

Generally, these machines are grouped on the basis of total number of axes upon which these operate. These axes are recognized by different letters such as:

  • Letters X and Y are for horizontal movement of the material.
  • Letter Z is for up and down as well as vertical movement.
  • Letter W is used for diagonal movement over a vertical plane.

Most of the machines can operate over three to five axes with some of the advanced CNC milling machines (like the 5 axes machines) requiring CAM programming to achieve optimal performance when machining complex geometries.


What is the benefit of using CNC Milling?

  • CNC milling machines are considered quite useful since these make it possible to create shapes which would otherwise be impossible to produce by utilizing manual techniques.
  • These are the ideal option whether you are looking for prototyping, want short run production of rather complex parts or interested in fabrication of precision components.
  • Any material which can be cut or drilled can be machined using CNC milling with great degree of precision (normally, 0.0001 inch or even better).
  • Milling process can be used for producing shapes and also various details in a work-piece such as holes, slots, grooves, notches and other specialty faces.


What are the basic elements of CNC Milling?

Usually, three elements are required for achieving high quality CNC milling, these are:

  • Cutter with required number of teeth and sharpness suitable for cutting a work piece.
  • Spinning of tool at very high speed so that the material can be adequately altered.
  • Suitable feed rate for moving the work piece through the machining process.


What are the different categories of CNC milling procedure?

Milling process can be categorized as face milling or peripheral milling. Let us briefly look at them here.

  • Face Milling: In this type of milling the cutting action takes place at cutter’s end corners. Normally, it is used for cutting flat bottomed cavities or flat surfaces into a work piece.
  • Peripheral Milling: Here the cutting takes place along circumference of milling cutter. Due to this type of cutting the cross section of the work piece gets shape of the milling cutter.

This type of peripheral milling is ideal for cutting threads, deep slots as well as gear teeth.


Types of Mills

There are different types of mills which can be used according to particular requirement, these can be:

  • Bed mill
  • Box mill
  • C-frame mill
  • Floor mill
  • Gantry mill
  • Horizontal boring mill
  • Knee mill
  • Planer style mill
  • Ram type mill
  • Turret mill


If you are looking for precision machining options then CNC milling would be worth looking at due to the high degree of precision which is possible in this process and the range of material which can be worked upon.