## Cutting Power for Face Milling

Cutting Power

Pc (kW) : Actual Cutting Power
ap (mm) : Depth of Cut
ae (mm) : Cutting Width
vf (mm/min) : Table Feed per Min.
Kc (MPa) : Specific Cutting Force
η: (Machine Coefficient)
Input the values.
ap(mm)
ae(mm)
ｖｆ(mm/min)
Kc(MPa)
η(Machine Coefficient)

Pc(kw)

（Problem）
What is the cutting power required for milling tool steel at a cutting speed of 80m/min. With depth of cut 2mm, cutting width 80mm, and table feed 280mm/min by Φ250 cutter with 12 inserts. Machine coefficient 80%.
First, calculate the spindle speed in order to obtain feed per tooth.
n=1000vc÷πDC=(1000×80)÷(3.14×250)=101.91min-1
Feed per Tooth fz=vf÷(z×n)=280÷(12×101.9)=0.228mm/tooth
Substitute the specific cutting force into the formula.
Pc=(2×80×280×1800)÷(60×106×0.8)=1.68kW
Kc
Work Material Tensile Strength
（MPa）
and Hardness
Specific Cutting Force Kc（MPa）
0.1
(mm/tooth)
0.2
(mm/tooth)
0.3
(mm/tooth)
0.4
(mm/tooth)
0.6
(mm/tooth)
Mild Steel 520 2200 1950 1820 1700 1580
Medium Steel 620 1980 1800 1730 1600 1570
Hard Steel 720 2520 2200 2040 1850 1740
Tool Steel 670 1980 1800 1730 1700 1600
Tool Steel 770 2030 1800 1750 1700 1580
Chrome Manganese Steel 770 2300 2000 1880 1750 1660
Chrome Manganese Steel 630 2750 2300 2060 1800 1780
Chrome Molybdenum Steel 730 2540 2250 2140 2000 1800
Chrome Molybdenum Steel 600 2180 2000 1860 1800 1670
Nickel Chrome Molybdenum Steel 940 2000 1800 1680 1600 1500
Nickel Chrome Molybdenum Steel 352HB 2100 1900 1760 1700 1530
Austenitic Stainless Steel 155HB 2030 1970 1900 1770 1710
Cast Iron 520 2800 2500 2320 2200 2040
Hard Cast Iron 46HRC 3000 2700 2500 2400 2200
Meehanite Cast Iron 360 2180 2000 1750 1600 1470
Grey Cast Iron 200HB 1750 1400 1240 1050 970
Brass 500 1150 950 800 700 630
Light Alloy (Al-Mg) 160 580 480 400 350 320
Light Alloy (Al-Si) 200 700 600 490 450 390
Light Alloy (Al-Zn-Mg-Cu) 570 880 840 840 810 720