RPM = 3.819 x SFM                  SFM = Cutter Diameter x RPM x .262
          Cutter diameter

IPM = RPM x FPT x no. of cutting edges

FPT = IPM / RPM / no. of cutting edges

CIPM MRR = IPM x WOC x DOC

Req’d HP = CIPM MRR / Material factor*
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RPM = Revolutions per minute   IPM = Inches per minute (feedrate)

FPT = Feed per tooth (chip thickness)   WOC = Width of cut

DOC = Depth of cut    SFM = Surface feet per minute    HP = Horsepower

CIPM MRR = Cubic inches per minute Metal removal rate
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*Material Factors

Mild Steel = 1       4140 = .5      Aluminum = 3~5       Cast Iron = .8
303 Stainless Steel = .7              304 Stainless Steel = .4
316 Stainless Steel = .5              17-4 Stainless Steel = .6