Chip Load Basics for CNC Milling

Chip load is a key parameter in milling. Understanding it helps you improve tool life and machining efficiency.

Chip load describes how much material each flute of the tool removes during one revolution. Choosing the correct chip load improves tool life, reduces heat and increases machining efficiency.

How chip load works

Chip load depends on spindle speed, number of flutes and feed rate. Too low and the tool rubs instead of cutting. Too high and the tool overloads, causing chatter or breakage. Most manufacturers specify recommended chip loads by material and tool diameter.

How to calculate chip load

The basic formula is:

chip load = feed rate / (rpm × number of flutes)
    

To invert the formula and calculate feed rate when chip load is known, you can use the CNC Feed Rate Calculator.

Common chip load mistakes

• Using the same chip load for all materials
• Ignoring tool diameter when selecting chip load values
• Running too low chip loads in stainless steel and titanium
• Using catalog chip loads but reducing feed too much for small tools

Mastering chip load is essential for efficient CNC milling. Start experimenting with different values and monitor tool wear to find the ideal range for your machine and material.