Surface Speed Calculator:
Enter the values of diameter, D(in) and RPM to determine the value of surface speed, SFM(ft/min).
Surface Speed:
Surface Speed, or Surface Feet per Minute (SFM), is the speed at which the outer surface of a rotating object moves in relation to a fixed point. It is a vital machining parameter that determines the cutting conditions for tools like drills, mills, and lathes.
SFM affects tool wear, surface finish, and overall efficiency. Using the appropriate SFM improves production rates and extends tool life.It depends on the diameter of the rotating part and the number of revolutions per minute (RPM).
SFM is used in both manual machining and CNC programming to define optimal cutting speeds for different materials.A larger diameter tool rotating at the same RPM will have a higher surface speed than a smaller one.
Over-speeding can overheat the tool, while under-speeding may cause poor-quality cuts.SFM is calculated in feet per minute (ft/min).
It standardizes machine settings and ensures consistency in operations. Often, tool manufacturers provide recommended SFM values for various materials.It is important to measure diameter accurately and ensure correct RPM input.
Machinists often refer to SFM charts for specific applications.Surface speed, SFM is directly proportional to diameter and RPM.Proper SFM minimizes downtime and reduces tool replacement price.
Surface Speed, SFM(ft/min) in feet per minute equals pi (π) multiplied by diameter, D(in) in inches, multiplied by revolutions per minute, RPM, divided by 12.
Surface Speed, SFM(ft/min)= 3.14 * D(in) * RPM / 12
SFM(ft/min)= surface speed in feet per minute, ft/min.
D(in) = diameter in inches, in.
RPM = revolutions per minute.
Surface Speed Calculation:
- A tool with a diameter of 2 inches rotates at 1500 RPM. Find the surface speed.
Given: D(in) = 2in, RPM = 1500.
Surface Speed, SFM(ft/min)= 3.14 * D(in) * RPM / 12
SFM(ft/min)= 3.14 * 2 * 1500 / 12
SFM(ft/min)= 9424.8 / 12
SFM(ft/min)= 785.4ft/min.
- A tool must operate at 500 ft/min surface speed using a diameter of 1.25 inches. Find the RPM.
Given: D(in) = 1.25in, SFM(ft/min)= 500ft/min.
Surface Speed, SFM(ft/min)= 3.14 * D(in) * RPM / 12
RPM = (SFM(ft/min)* 12) / 3.14 * D(in)
RPM = (500 * 12) / 3.14 * 1.25
RPM = 6000 / 3.927
RPM = 1527.73RPM.