Formulae for Face Milling

Inch

Cutting Speed(vc)
Cutting Speed
vc(SFM):Cutting Speed
DC(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.
DC(inch)
n(min-1)
vc(SFM)


image
(Problem)
What is the cutting speed when main axis spindle speed is 350min-1 and the cutter diameter is ø5" ?
(Answer)
Substitute π=3.14, DC=5", n=350 into the formulae.
vc=π×DC×n÷12=3.14×5"×350÷12=457.9SFM
The cutting speed is 457.9SFM.


Feed Per Tooth(fz)
FORMULAE
vf(inch/min):
Table Feed per Min.

z:Insert Number
n(min-1):
Main Axis Spindle Speed (Feed per Revolution f=z
xfz)
fz(IPT):Feed per Tooth
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(IPT)


image
(Problem)
What is the feed per tooth when the main axis spindle speed is 500min-1, number of insert 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)
FORMULAE
vf(inch/min): Table Feed per Min.
z:Insert Number
n(min-1): Main Axis Spindle Speed
fz(IPT):Feed per Tooth

image
(Problem)
What is the table feed when feed per tooth is .004IPT, number of insert 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)
FORMULAE
L(inch):Total Table Feed Length (Workpiece Length: (l)+Cutter Diameter:DC))
vf(inch/min):Table Feed per Min.
Tc(min):Cutting Time
Input the values. L(inch) vf(inch/min)

Tc(min)
sec.

image
(Problem)
What is the cutting time required for finishing 4" width and 12" length surface of a cast iron (GG20) block when the 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 formula.
Tc=16÷32=0.5(min)

The answer is 30 sec.


Metric

Cutting Speed(vc)
計算式
*Divide by 1000 to change to m from mm.
DC(mm);Cutter Diameter
π(3.14):Pi
n(min-1):Main Axis Spindle Speed

vc(m/min):Cutting Speed
Check the item you want to calculate, input values in the two boxes, and then press the Calculate button.
DC(mm)
n(min-1)
vc(m/min)


image
(Problem)
What is the cutting speed when main axis spindle speed is 350min-1 and the cutter diameter is ø125 ?
(Answer)
Substitute π=3.14, DC=125, n=350 into the formula.
vc=(π•DC•n)÷1000=(3.14×125×350)÷1000
=137.4m/min

The cutting speed is 137.4m/min.


Feed Per Tooth(fz)
FORMULAE
vf(mm/min):
Table Feed per Min.

z:Insert Number
n(min-1):
Main Axis Spindle Speed (Feed per Revolution f=z
xfz)
fz(mm/t.):Feed per Tooth
Check the item you want to calculate, input values in the three boxes, and then press the Calculate button.
vf(mm/min)
z
n(min-1)
fz(mm/t.)


image
(Problem)
What is the feed per tooth when the main axis spindle speed is 500min-1, number of insert is 10, and table feed is 500mm/min?
(Answer)
Substitute the above figures into the formula.
fz=Vf÷(z×n)=500÷(10×500)=0.1mm/tooth
The answer is 0.1mm/tooth.


Table Feed(vf)
FORMULAE
vf(mm/min): Table Feed per Min.
z:Insert Number
n(min-1): Main Axis Spindle Speed
fz(mm/tooth):Feed per Tooth

image
(Problem)
What is the table feed when feed per tooth is 0.1mm/t., number of insert is 10, and main axis spindle speed is 500min-1?
(Answer)
Substitute the above figures into the formula.
vf=fz×z×n=0.1×10×500=500mm/min
The table feed is 500mm/min.


Cutting Time(Tc)
FORMULAE
L(mm):Total Table Feed Length (Workpiece Length: (l)+Cutter Diameter:DC))
vf(mm/min):Table Feed per Min.
Tc(min):Cutting Time
Input the values.
L(mm)
vf(mm/min)

Tc(min)
sec.

image
(Problem)
What is the cutting time required for finishing 100mm width and 300mm length surface of a cast iron (JIS FC200) block when the cutter diameter is ø200mm, the number of inserts is 16, the cutting speed is 125m/min, and feed per tooth is 0.25mm. (spindle speed is 200min-1
(Answer)
Calculate table feed per min
vf=0.25×16×200=800mm/min

Calculate total table feed length.
L=300+200=500mm

Substitute the above answers into the formula.
Tc=500÷800=0.625(min)

0.625×60=37.5(sec). The answer is 37.5 sec.

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