Calculate feed per tooth or feed rate from spindle speed and cutter teeth, with chip load, in mm/min or in/min for milling and machining.
Feed Per Tooth Formula
The following formula is used to calculate the feed per tooth (fz) for a milling operation:
fz = (vf * n) / (z * ap)
Variables:
- fz is the feed per tooth
- vf is the feed rate
- n is the spindle speed
- z is the number of teeth on the cutter
- ap is the axial depth of cut
To calculate the feed per tooth, multiply the feed rate by the spindle speed, then divide the result by the product of the number of teeth on the cutter and the axial depth of cut.
What is a Feed Per Tooth?
Feed Per Tooth, often abbreviated as FPT or Ft, is a critical parameter in machining operations, particularly in milling. It refers to the distance that the mill or cutter travels along the workpiece for every single tooth pass. This measurement is typically given in inches or millimeters and is crucial in determining the speed and feed rate of the milling operation. The Feed Per Tooth is directly related to the surface finish of the workpiece, the tool life, and the rate of material removal. Too high a feed per tooth can result in tool breakage or poor surface finish, while too low a feed per tooth can lead to inefficient machining and excessive tool wear. Therefore, it is essential to calculate and set the correct Feed Per Tooth for each specific machining operation.
