MITSUBISHI MATERIALS CORPORATION
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FORMULAS FOR MILLING

CUTTING SPEED (vc)
Formula
vc (SFM)
:Cutting Speed
D1 (inch)
:Cutter Diameter
π (3.14)
:Pi
n (min-1)
:Main Axis Spindle Speed
Check the item you want to calculate, input values in the two boxes, and then press the Calculate button.
D (inch)
n (min-1)
vc


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(Problem) :
What is the cutting speed when main axis spindle speed is 350min-1 and cutter diameter is Ø5" ?

(Answer):
Substitute π3.14, D=5", n=350 into the formulae.
vc =π×D×n÷12=3.14×5"×350÷12= 457.9SFM
The cutting speed is 457.9SFM.

FEED PER TOOTH (fz)
Formula
fz (IPT)
:Feed per Tooth
z
:Insert Number
vf(inch/min)
:Table Feed per Min.
n (min-1)
:Main Axis Spindle Speed (Feed per Revolution fr=z x fz)
Check the item you want to calculate, input values in the three boxes, and then press the Calculate button.
vf (inch/min)
z
n (min-1)
fz

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(Problem) :
What is the feed per tooth when the main axis spindle speed is 500min-1, insert number is 10, and table feed is 20inch/min ?

(Answer):
Substitute the above figures into the formulae.
fz =Vf÷(z×n)=20÷(10×500) = .004IPT
The answer is .004IPT.

TABLE FEED (vf)
Formulate
vf(inch/min)
:Table Feed per Min.
fz (IPT)
:Feed per Tooth
n (min-1)
:Main Axis Spindle Speed
z
:Insert Number
Input the values
fz
z
n(min-1)

vf

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(Problem) :
What is the table feed when feed per tooth is .004IPT, insert number is 10, and main axis spindle speed is 500min-1?

(Answer):
Substitute the above figures into the formulae.
vf = fz×z×n = .004IPT×10×500 = 20inch/min
The table feed is 20inch/min.

CUTTING TIME (Tc)
Formulate
Tc (min)
:Cutting Time
vf(inch/min)
:Table Feed per Min.
L (inch)
:Total Table Feed Length (Workpiece Length(l)+Cutter Diameter(D1)
Input the values
L (inch)
vf (inch/min)

Tc (min)
second (s)

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(Problem) :
What is the cutting time required for finishing 4" width and 12" length surface of a cast iron (GG20) block when cutter diameter is Ø4", the number of inserts is 16, the cutting speed is 410SFM , and feed per tooth is .01. (spindle speed is 200min-1)

(Answer):
Calculate table feed per min vf=.01×16×200=32inch/min
Calculate total table feed length. L=12+4=16inch
Substitute the above answers into the formulae.
Tc =16÷32= 0.5(min)
The answer is 30 sec.