Drill SFM Calculator


About Drill SFM Calculator (Formula)

The Drill Surface Feet per Minute (SFM) Calculator is a tool used to calculate the optimal rotational speed for a drill bit based on the type of material being drilled and the diameter of the drill bit. SFM is a critical parameter in machining operations, as it determines the speed at which the drill bit should rotate to achieve optimal cutting performance and tool life. The formula for calculating Drill SFM is as follows:

SFM = (Cutting Speed × 12) / π × Drill Diameter


  • SFM: The Surface Feet per Minute, indicating the rotational speed of the drill bit.
  • Cutting Speed: The recommended cutting speed for the specific material being drilled, often measured in feet per minute (ft/min).
  • π (Pi): A mathematical constant approximately equal to 3.14159.
  • Drill Diameter: The diameter of the drill bit used for the operation, measured in inches.

The correct SFM value ensures that the drill bit removes material efficiently without causing excessive wear or damage. Using the wrong SFM can result in poor hole quality, reduced tool life, and potential workpiece damage.

The Drill SFM Calculator simplifies the process of determining the appropriate rotational speed for drilling operations, assisting machinists, engineers, and metalworkers in achieving accurate and efficient cutting results.

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