Page 467 - Hartner

Coolant diagrammes
Coolant pressure and flow rate

for carbide twist drills with internal coolant ducts

60 24
22
50 16
20
18
coolant pressure [bar] 20 minimum 14 coolant flow rate [l/min]
40
12
30
10
volume
8
pressure
10 minimum 6 4
2
A 10 12.5 15 17.5 20 22.5 25
B 5 7.5 10 12.5 15 17.5 20
drill diameter [mm]
A = range of diameters for tools with central internal coolant channel
B = range of diameters for tools with twisted internal coolant feed

for Multiplex-twist drills with internal coolant ducts

coolant pressure [bar] 16 8 l/min 80
14
12
60
10
40

2 6 4 bar 20
10 20 30 40 50 60 70 80 90 100 210
drill diameter [mm]

Drilling emulsion can be used as a coolant It is absolutely essential here that you be poor or the tool may even be
lubricant when drilling with interchangeable use a high-performance coolant aggregate. damaged. If possible, the solid particles
blades made of HSS-Co and carbide; it can If there is insufficient coolant pressure in the coolant should not be larger than
be used in the usual proportions of 1:20. and quantity, the drilling surface may 50 μm.

48
44
40
36
32
28
24
20
16 461
12
8
4
20 40 60 80 100 120140 160180 200 210