Page 305 - ISCAR(HOLE_MAKING_CATALOG_65)

USER GUIDE

Standard Gundrill Length Calculations GUNDRILLS

H Example
Drilling of a ø10x500 depth hole on a gundrill machine with
D ø25x70 mm driver code No. 57 (See page 302)
D=10 W=500 LA=70 B=250 (or per experience)
N W B F LA L=N+W+B+F+LA
Ls L=(35-10)+500+250+13+70=858 (OAL)
L
Ls=N+W+B=770 (flute length)
Standard Gundrill Carbide Head Length
Ordering Code
H For example:
D and Ls are available as standard
STGD-10000-0858-57-IC08
Diameter Range Head Length
D
2.50-3.80 20
3.80-4.05 23
4.05-5.05 25
D= Cutting diameter 5.05-6.55 30
H= Carbide length 6.55-11.05 35
N= Regrinding area = H-D 11.05-18.35 40
W= Hole depth 18.35-21.35 45
B= Chip evacuation area = For typical
gundrill machines, 250 mm 21.35-23.35 50
= For machining centers, 2xD (minimum 15 mm) 23.35-26.35 55
F= 10 mm. 26.35-32.00 65
LA = Driver length Note: regrindable length=H-D
LS = Flute length
L= Overall length

Pressure and Coolant Flow Rate for Gundrills

Bar L/min
120 120
110 L/D>100 Q 110
100 P 100
90 90
80 80
70 L/D<100 70
60 60
50 50
40 40
30 L/D>100 30
20 L/D<100 20
10 10
Ø 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 40 mm
Drilling Diameter

Q l/min P bar
Gundrill Lubrication and Cooling Guidelines for Optimal Gundrill Performance
The best performance is obtained by using oil. • It is recommended to use a strong coolant flow for
On equipment that uses water-soluble fluids (i.e. efficient chip flushing and cooling of the cutting edge
machining centers and CNC machines), a concentration • It is recommended to use a filter under 20 µm
between 10% and 15% is recommended. • Note: Improper filtration may result in interrupted flow
of lubricating oil. This creates a sticky surface on the
bearing pads and leads to premature wear of the tool
and overloading the coolant pump and spindle seals
• The coolant temperature should be between 20 and 22º C.
Note: Above 50º C the viscosity of the coolant is reduced by 50% and
becomes ineffective.

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