MITSUBISHI MATERIALS CORPORATION
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FORMULAE FOR MILLING (Metric)

¨CUTTING SPEED (vc)

Formula
* Divide by 1,000 to change to m from mm.

vc (m/min) : Cutting Speed
D1 (mm) : Cutter Diameter
p (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.
D1 (mm)
n (min-1)
vc (m/min)
Graphic Image (Problem)
What is the cutting speed when main axis spindle speed is 350min-1 and cutter diameter isø125?
(Answer)
Substitute p=3.14, D1=125, n=350 into the formulae.

vc=(p×D×n)÷1000=(3.14×125×350)÷1000 =137.4(m/min)

The cutting speed is 137.4 m/min. 
¨FEED PER TOOTH (fz), TABLE FEED (vf)

Formula

Formula

fz (mm/tooth) : Feed perTtooth
z : Insert Number
vf (mm/min) : Table Feed per Min.
n (min-1) : Main Axis Spindle Speed
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/tooth)
Graphic Image (Problem)
What is the feed per tooth when the main axis spindle speed is 500min-1, insert number is 10, and table feed is 500mm/min?
(Answer)
Substitute the above figures into the formulae.

fz=vf÷(z×n)=500÷(10×500)=0.1mm/tooth

The answer is 0.1mm/tooth.
Graphic Image (Problem)
What is the table feed when feed per tooth is 0.1mm/tooth, insert number is 10, and main axis spindle speed is 500min-1?
(Answer)
Substitute the above figures into the formulae.

vf=fz×z×n=0.1×10×500=500mm/min

The table feed is 500 mm/min.
¨CUTTING TIME (Tc)

Formula

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

Tc (min)
second (s)
Graphic Image (Problem)
What is the cutting time required for finishing 100 mm width and 300 length surface of a cast iron (GG20) block when cutter diameter is ø200, the number of inserts is 16, the cutting speed is 125m/min, and feed per tooth is 0.25 mm. (spindle speed is 200 min-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 formulae.

Tc=500÷800=0.625(min)

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