## Cutting Power for Turning

Cutting power(Pc)

Pc (kW) : Actual Cutting Power
ap (mm) : Depth of Cut
f (mm/rev) : Feed per Revolution
vc (m/min) : Cutting Speed
Kc (MPa) : Specific Cutting Force
n: (Machine Coefficient)
Input the values.
ap(mm)
f(mm/rev)
ｖｃ(m/min)
Kc(MPa)
η(Machine Coefficient)

Pc(kw)

（Problem）
What is the cutting power required for machining mild steel at cutting speed 120m/min with depth of cut 3mm and feed 0.2mm/rev (Machine coefficient 80%) ?

Substitute the specific cutting force Kc=3100MPa into the formula.
Pc=(3×0.2×120×3100)÷(60×103×0.8)=4.65(kW)
Kc
Work Material Tensile Strength(（MPa）
and Hardness
Specific Cutting Force Kc（MPa）
0.1
(mm/rev)
0.2
(mm/rev)
0.3
(mm/rev)
0.4
(mm/rev)
0.6
(mm/rev)
Mild Steel 520 3610 3100 2720 2500 2280
Medium Steel 620 3080 2700 2570 2450 2300
Hard Steel 720 4050 3600 3250 2950 2640
Tool Steel 670 3040 2800 2630 2500 2400
Tool Steel 770 3150 2850 2620 2450 2340
Chrome Manganese Steel 770 3830 3250 2900 2650 2400
Chrome Manganese Steel 630 4510 3900 3240 2900 2630
Chrome Molybdenum Steel 730 4500 3900 3400 3150 2850
Chrome Molybdenum Steel 600 3610 3200 2880 2700 2500
Nickel Chrome Molybdenum Steel 900 3070 2650 2350 2200 1980
Nickel Chrome Molybdenum Steel 352HB 3310 2900 2580 2400 2200
Hard Cast Iron 46HRC 3190 2800 2600 2450 2270
Meehanite Cast Iron 360 2300 1930 1730 1600 1450
Grey Cast Iron 200HB 2110 1800 1600 1400 1330