Know the basics of CNC Router Bits

2 Mins read

It is necessary to understand that without using the correct bits, even any perfect CNC rig is likely to be going this far. Bits will be essential for CNC routers to determine carving material, type and resolution.

Although CNC machines are used to open up various types of creative possibilities, it is the bit that is considered to do the magic. It determines if you derive an okay or perfect design. Moreover, it does make a difference between increasing material costs or reducing waste.


Bit is typically used for removing materials. Routers initially, were used as handheld tools that ball-bearing pilots or templates guided. They got moved around the work piece manually. However, routers these days get controlled with computers to determine precisely the toolpath. Such routers do need bits for creating intricate cuts. The design and material range that are cut by those Router Bits seem to have developed significantly in diversity. There are several types in the market today.


You need to familiarize yourself with certain CNC routing jargon a few of which are given below:

  • Toolpath: The CNC equipment follows this coded route to cut. It acts as an effective guide for the equipment.
  • Speed rate: It is the Spindle’s rate and is represented in RPM (revolutions per minute).
  • Feed rate: It shows how quickly the bit laterally moves through the material. Generally, it is measured in feet per minute or IPM. If chips are extremely large, then reduce feed rate to avoid ruining the bit.
  • Chip Load: It is considered to be the pieces removed by the CNC bit from material or chip size. Rather, it can be termed to be the chip size or thickness per cutting edge made with every revolution. As smaller chips are found to generate more heat during cutting process, chip load is stated to be crucial. Smaller chips do not get ejected fast properly. Rather, they get re-cut to smaller pieces, thereby generating more heat. It results in premature bit failure as heat gets transferred to cutting tool. Being of appropriate size, the chips carry away heat, thereby prolonging tool life.
  • It is a known aspect that chip load is equivalent to feed rate (IPM or inches per minute).it is then divided by per minute revolutions and later multiplied by flutes number. Chip load value ensures choosing the bit’s appropriate diameter or size.

Getting to know some CNC Router Bits related terminology can help choose the right tool.