What is Chip Load?
Chip load, often referred to as Inches Per Tooth (IPT), is the actual thickness of the material removed by a single cutting edge (flute) of a tool during one revolution. It is one of the most critical parameters in CNC machining, as it determines the health of your cutting tool, the finish quality of the workpiece, and the overall efficiency of the machining process.
Why is Chip Load Important?
Calculating the correct chip load is essential for two main reasons: tool life and heat dissipation. If the chip load is too small, the tool will rub against the material rather than cutting it, generating excessive heat and causing the tool to dull prematurely. Conversely, if the chip load is too high, the physical forces on the tool can cause it to deflect or snap under the pressure.
The Chip Load Formula
The standard formula used by this calculator is:
Chip Load = Feed Rate / (RPM × Number of Flutes)
By adjusting your Spindle Speed (RPM) or your Feed Rate (IPM), you can dial in the perfect chip load recommended by your tool manufacturer for specific materials like aluminum, hardwood, or plastics.
How to Use This Calculator
To use the tool, follow these three simple steps:
- Enter the Feed Rate in Inches Per Minute (IPM).
- Enter the Spindle Speed in Revolutions Per Minute (RPM).
- Enter the Number of Flutes (cutting edges) on your end mill.
- Click "Calculate" to see the result in Inches Per Tooth (IPT).
Frequently Asked Questions
What happens if my chip load is too low?
A low chip load leads to "rubbing." This creates friction heat which can melt plastics, burn wood, and ruin the temper of metal-cutting tools.
Can I use this for metric units?
Yes, the logic remains the same. If you use Millimeters Per Minute (mm/min) for Feed Rate, the result will be Millimeters Per Tooth (mmPT).