Feed Rate – The Complete Guide to CNC Machining Speeds and Efficiency

Introduction: What Is Feed Rate?

In CNC machining, feed rate is one of the most important parameters. It refers to the speed at which the cutting tool advances into the workpiece during machining. Feed rate determines material removal rate, surface finish, tool life, and overall efficiency of the process.

Too slow, and productivity suffers. Too fast, and the tool may break or the workpiece surface may be damaged. Mastering feed rate is therefore critical for achieving precision, efficiency, and cost-effective manufacturing.

The Definition of Feed Rate

Feed rate is usually expressed in:

• mm/min (millimeters per minute) or in/min (inches per minute) for linear feed.

• mm/rev (millimeters per revolution) or in/rev (inches per revolution) in turning.

• mm/tooth (millimeters per tooth) for milling, depending on the number of cutting edges.

It is controlled by the CNC program using the F code in G-code. Example: