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Symbol Chart

D = Depth of Cut (in inches)
d = Diameter of Cutter (in inches)
T = Number of Teeth in Cutter
W = Width of Cut (in inches)
K = Constant (cubic inches per minute per HPc)
R.P.M. = Revolutions per Minute
S.F.M. = Surface Feet per Minute
F.P.R. = Feed per Revolution (in inches)
I.P.M. = Feed (travel in inches per Minute)
F.P.T. = Feed per Tooth (in inches)
HPc = Horsepower at the Cutter


Calculating R.P.M.
R.P.M. = (12 × ) ÷ (Pi × )


Calculating S.F.M.
S.F.M. = (Pi × × ) ÷ 12


Calculating F.P.R.
F.P.R. = ÷


Calculating I.P.M.
I.P.M. = × ×


Calculating F.P.T.
F.P.T. = ÷ ( × )


Calculating HPc
HPc = ( × × ) ÷


Calculating Number of Teeth
No. of Teeth = ÷ ( × )


Calculating Maximum Number of Teeth
Max. No. of Teeth = ( × ) ÷ ( × × × )