Machining Calculators

Chip Thinning is necessary in Trochoidal Milling (High Efficiency Machining, Dynamic Milling, etc) tool paths due to a reduced radial stepover. Click here for more information. PLEASE NOTE: Chip Thinning has already been taken into account for the following series: TMR, TMS

Chip Thinning is necessary in Trochoidal Milling (High Efficiency Machining, Dynamic Milling, etc) tool paths due to a reduced radial stepover. Click here for more information. PLEASE NOTE: Chip Thinning has already been taken into account for the following series: TMR, TMS

Machining Formulas
Common machining formulas can be found below. We also have a few handy calculators to help with some of these calculations.

Cutting Speed Formulas Mill or Lathe
(RPM = Revolutions Per Minute)  3.82 x SFM ÷ Diameter
(SFM = Surface Feet Per Minute )  0.262 x Diameter ( Tool or Stock ) x RPM

Metric Conversion
(SFM to Surface Meters Per Minute) SFM x .3048
(Surface Meters Per Minute to SFM) SMPM x 3.2808399

Metal Removal Rate
MRR =12 × DOC × Feed × SFM

Milling Feed Rate Formulas
Inches Per Minute (IPM) = FPT x T x RPM
Feed Per Revolution (FPR) = IPM ÷ RPM
Feed Per Tooth (FPT) = IPM ÷ (RPM x T)

Metric Conversion
Convert Inches Per Revolution (IPR) to Inches Per Minute (IPM) = IPR x RPM
Convert Inches Per Minute (IPM) to Inches Per Revolution (IPR) = IPM ÷ RPM
Convert Inches Per Revolution (IPR) to Millimeters Per Revolution (MMPR) = IPR x 25.40
Millimeters to Inches = Millimeters x .03937 = Inches
Inches to Millimeters = Inches x 25.4 = Millimeters
Meters to Inches = Meters x 39.37 = Inches
Inches to Meters = Inches x .0254 = Meters
Meters to Feet = Meters x 3.2808 = Feet
Feet to Meters = Feet x .3048 = Meters
Meters to Yards = Meters x 1.0936 = Yards

Milling Formulas
(CTM = Cutting Time in Minutes)  L ÷IPM
(CTS = Cutting Time in Seconds)  L ÷IPM x 60
(IPM = Inches per Minute)  RPM x IPT x # of Teeth (flutes)
(MRR = Metal Removal Rate /Cubic Inches per Minute)  W x D x IPM