
143Cutting Cylindrical Surfaces
The main cutting force F
v
becomes
vSc
The drilling torque M becomes
MF
==
v
Nmm
20 000,
The rate of material removal VRR can be calculated from
VRR =
=2
A
V
V
TABLE 5.4 (continued)
Recommended Feeds and Speeds for Drilling Various Materials
Material Drilled
Hardness
(HB)
Drill
Material
Cutting
Speed
(m/min)
Feed
Rate
(mm/rev)
Helix
Angle (°)
Point
Angle (°)
Precipitation-
hardened
150–200 HSS-Co 15 X 25–35 118–135
Tool 196 HSS 18 Y 25–35 118
241 HSS 15 Y 25–35 118
Titanium
Pure 110–200 HSS 30 X 30–38 135
α and α−β
300–360 HSS-Co 12 Y 30–38 135
B 275–350 HSS-Co 7.6 W 30–38 135
Zink alloys 80–100 HSS 76 Z 32–42 118
Source: ...