WHAT is the formula in getting the rpm in lathe?

To calculate the RPM (revolutions per minute) for a lathe, you can use the formula: RPM = (Cutting Speed × 12) / (π × Diameter). Here, the cutting speed is typically given in feet per minute (FPM), and the diameter is in inches. This formula helps determine the appropriate spindle speed for different materials and tool types to ensure effective machining.