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Running calculations before a milling project can help you to improve your efficiency and results while avoiding mistakes. As with many other machining operations, milling is most successful with proper planning. Of course, before you can perform any calculations for your end mill, you need to know what you will be working out and why.

Common Formulas for Milling Operations: Speed, Feed & Rate

Some of the most common operations for milling require speed, feed, and rate calculations. These are the formulas and uses for each of these:

  • Speed: The mill speed in rotations per minute is calculated based on the surface feet per minute and the tool diameter (D) in inches. The formula is RPM = (SFM * 12) / (D * pi). It calculates the difference between the velocity of the tool and the velocity of the workpiece.
  • Feed: The cutting feed-in inches per minute can be calculated based on the feed per tooth multiplied by the number of teeth on the cutter (Z). The formula is IPR = FPT * Z. It determines the feed-in inches per rotation of the mill.
  • Rate: The feed rates multiples these two together. The formula is IPM = RPM * IPR. It calculates the feed rate per minute of work.

These calculations are relatively easy, and you can work them out by hand. However, a lot of people prefer to use a machining calculator online. It is a simple way to ensure fast, accurate, and easy calculations. Even with a physical engineering calculator, it is easy to make a mistake when typing in the formula. An online calculator only requires a browser and makes running your calculations simple.

The Ultimate MRR and Durability

Another common calculation for milling is the material removal rate, sometimes called the metal removal rate. This is a simple calculation to determine how many cubic inches of material you will remove during a minute of milling.

To calculate this, you need to know the feed rate, the depth of cut, and the width of cut. The formula for this is MRR = IPM * DOC * WOC. Again, this can be worked out easily using an end mill calculator.

These calculations are essential for determining the durability of the final product. Removing too much material too quickly can weaken the material. Conversely, going too slowly can result in extremely low productivity. For any machine operator, it is important to balance these competing requirements. Having the right calculator to help with the job can make planning the project simpler.

Kennametal offers engineering calculators to help with a variety of machining needs. These complement our tools perfectly by helping you to use them to achieve superior results.

Get the Right Tools and Resources for End Milling

Discover more about making end mill calculations and using our other machining calculators. Our resources are available conveniently on our website. When you are using your high-quality Kennametal tools, you will also be able to make smart decisions thanks to our powerful calculators. Give them a try today.