Surface Speed Calculator

Formula

To calculate the Surface Speed (SFM):

\[ SFM = \pi \times D \times RPM \]

Where:

\(SFM\) is the Surface Speed (distance/minute)
\(D\) is the Stock Diameter
\(RPM\) is the Rotations Per Minute of the spindle

Surface Speed Definition

A surface speed, often referred to as SFM, is a term used in machining to describe the tangential velocity of a rotating piece of stock in a spindle. This unit is used in converting the spindle rotation into the velocity of this stock which is used for determining certain feed rates etc. for machining the material.

Example Calculation

Let's assume the following values:

Stock Diameter (\(D\)) = 2 inches
Rotations Per Minute (\(RPM\)) = 1000

Using the formula:

\[ SFM = \pi \times 2 \times 1000 = 6283.19 \text{ inches/minute} \]

The Surface Speed is 6283.19 inches/minute.