Drilling calculation formula
    1. Processing time Tc [sec]
    Tc
    =
    60 x H x π x DC x i
    f x vc x 1,000
    =
    60 x H x i
    vf
    2. Required power Pc [kW]
    Pc
    =
    HB x DC0.68 x vc1.27 xf0.59
    36,000
    3. Cutting speed vc [m/min]
    vc
    =
    π x DC x n
    1,000
    4. Spindle speed n [min-1]
    n
    =
    vc x 1,000
    π x DC
    5. Feed per revolution f [mm/rev]
    f
    =
    vf x π x DC
    vc x 1,000
    =
    vf
    n
    6. Feed rate vf [mm/min]
    vf
    =
    f x vc x 1,000
    π x DC
    =
    n x f
    7. Axial force F [N]
    F
    =
    0.24 x HB x DC0.95 x f 0.61 x 9.8
    8. Torque Mc [N･m]
    Mc
    =
    Pc x 30 x DC
    vc
    =
    Pc x 30 x 103
    π x n
    9. Chip discharge Q [cm3/min]
    Q
    =
    π2 x DC3
    vc x f x 106
    =
    π x DC2
    n x f x 1,000
    Brinell hardness of cut material HB Approximate value
    P
    Non-alloy steel150 HB
    Low-alloy steel200 HB
    High alloy steel300 HB
    M
    Ferritic system150 HB
    Austenite system200 HB
    K
    Malleable cast iron180 HB
    Gray cast iron220 HB
    Nodular cast iron300 HB
    N
    Aluminum alloy100 HB
    Copper alloy250 HB
    S
    Fe base200 HB
    Ni base220 HB
    Co base300 HB
    Ti base350 HB
    H
    High hardness steel 50-55HRC500 HB
    High hardness steel 60-63HRC700 HB
    • TcProcessing time[sec]
    • PcRequired power[kW]
    • vcCutting speed[m/min]
    • nSpindle speed[min-1]
    • fFeed per revolution[mm/rev]
    • vfFeed rate[mm/min]
    • FAxial force[N]
    • McTorque[N·m]
    • QChip discharge[cm3/min]
    • DCThe blade diameter of the drill[mm]
    • HDrilling depth[mm]
    • iNumber of holes[pcs]
    • HBBrinell hardness of cut material[HB]
    • ※ π ≒ 3.14