Drilling
 

Formulas


Cutting speed (vc)
m/min (ft/min)​		 Spindle speed (n)
rpm​

​		 ​
​ ​
Feed per revolution (fn)
mm/r (inch/r)​		 Penetration rate (vf)
mm/min (inch/min)​
​ ​
​ ​
Metal Removal rate (Q)
cm³/min (inch³/min)​		 Machining time (Tc)
min​
​

 

Net power requirement (Pc)
kW (HP)​
 Torque (Mc)
Nm (lbf ft)​

​		 ​​
​ ​
Specific cutting force (kc)
Nm/mm² (lbf/inch²)​		 Feed force, kc (Ff)
N ​
​

 

Solid carbide drills:
fz = fn/2 
KAPR = 70°
γ0 = 30°

Indexable insert drills:
fz = fn
γ0 = 15°

CoroDrill 880
Dia 12-13.99: KAPR=79°
Dia 14-63.5: KAPR=88°
 
CoroDrill 881
KAPR: 74-84°​

 


CoroDrill® 880

​

 

Parameter Meaning​ Metric unit​
DC​ Drill diameter​ mm​
vc​ Cutting speed​ m/min​
n​ Spindle speed​ rpm​
Q​ Metal removal rate​ cm3/min​
fn​ Feed per revolution​ mm/r​
fz​ Feed/edge​ mm​
vt​ Penetration rate​ mm/min​
Tc​ Machining time​ min​
lm​ Machining drilling length​ mm​
Pc​ Net power​ kW​
Mc​ Torque​ Nm​
Ft​ Feed force​ N​