80% Core - Speeds and Feeds
Parameter
Formulas
Cutting Speed
(SFM)
(SFM)
SFM= .262 x D1 x RPM
Revolutions Per Minute
(RPM)
(RPM)
RPM = 3.82 x (SFM/D1)
Feed Rate
(inches per minute)
(inches per minute)
F1 = F2 x N x RPM
Feed Per tooth
(inches)
(inches)
F2 = F1/(N x RPM)
Cutting Time
(minutes)
(minutes)
T = L/F1
Rate of Metal removal
(cubic inches per minute)
(cubic inches per minute)
MRR = W x D xF1
Symbol Definitions
D1 = Diameter of milling Cutter (inches)
RPM = Revolutions per minute
SFM = Cutting speed (feet per minute)
F1 = Feed rate (inches per minute)
F2 = Feed (inches per tooth)
N = Number of teeth in cutter
MRR = Rate of metal removed (cubic inches per minute)
T = Cutter time (minutes)
L = Length of cut (inches)
D = Depth of cut (inches)
W = width of cut (inches)
Type Of Application
Speed (SFM)
1/32"
1/16"
3/32"
1/8"
3/16"
1/4"
5/16"
3/8"
1/2"
Finishing
500
0.00015
0.0003
0.0004
0.0006
0.0009
0.0012
0.0015
0.0018
0.0025
Roughing & Semi Finishing
250
0.0005
0.001
0.0015
0.002
0.003
0.004
0.005
0.006
0.008
Reduce feed rate by 20% for every 2" increment.