Page 51 - HOLE_MAKING_CATALOG_INCH_2022_P187-P236

USER GUIDE

General - Calculations

-1
Spindle Speed (min ) Example
c
n= v ∙3.82 Drill DR 220-044-25-07-2D-N (.875”) - Material No. 4

π ∙ D
kc=319080 psi
k=90º, sin k=1
vc=650 sfm CMh=50 $/h η=0.75 SOLID CARBIDE DRILLS
Cutting Speed (sfm) km=1 kf=1 f=.006 inch/rev L=1” h=5”
π ∙ D ∙ n
650 ∙ 3.82
vc = 1000 n = vc ∙ 3.82 π ∙ .875 = 2838 min -1
=

π ∙ D
Table Feed (in/min) vf = f ∙ n=.006 ∙ 2838 = 17.0 inch/min
vf = f ∙ n
=
Q = vf ∙ π ∙ D 2 434 ∙ 3.14 ∙ (22) 2

4

4
Material Removal Rate (in /min) = 10.24 in /min
3
3
f
Q= v ∙ π ∙ D 2 Pc = Q ∙ Kc ∙ sin k
4000

395890 ∙ η

= 10.24 ∙ 319000 ∙ 1 =10.89 HP

Power Requirement (kW) 395890 ∙ 0.75
D 2
Q
Pc = 395890 ∙ η ∙ kc ∙ sin k Mc = f ∙ Kc ∙ ∙ sin k

10000
8

.006 ∙ 319000 .875
Torque (lbf*in) = 10000 ∙ ∙ 1 ∙1 = 183 lbf ∙ in

8

D
D 2
Mc = f ∙ k c 8 Ff = .630 ∙ ∙f ∙ Kc ∙ sin k
∙ ∙ sin k∙km
1000

2
= 0.63 ∙ .875 ∙ .006 ∙ 319000 ∙ 1 ∙1 = 528 lbf
2
Feed Force (approx.) (lbf)
D L+h 1+5
Ff = 0.63 ∙ ∙ f∙kc∙sin k∙kf Tc = = = .09 min/piece

2
17.2
V f
50 ∙ 0.09
Machining Time (min/piece) Cc = CMh ∙ Tc = 60
60

Tc = L+h = .073 $/piece
v f
Machining Cost ($/piece) kc Values
Material Group Kc (ksi) Material Group Kc (ksi)
Cc = C Mh ∙Tc 1 2 290 19 131

60

305
145
20
3 312 21 73
f Feed/rev IPR 4 319 22 116
kc Material specific cutting force PSI 5 319 23 116
h Distance from drill point to workpiece before feeding inch 6 305 26 102
L Depth of hole inch 7 305 27 102
CMh Cost/machine hour $/h 8 305 28 247
η Machine efficiency % 9 305 31 435
k 90º }180° bottom drills 10 363 32 450
sin k 1 DR... 11 471 33 479
k 70º }140° point angle drills 12 334 34 479
sin k 0.94 13 406 35 464
36
247
377
14
Drill Geometry Coeficient 15 160 37 247
DCM DCN SCD 16 189 38 667
km 1 0.85 0.85 17 160 39 682
kf1 0.85 0.85 18 261 40 667
41 653
235