Page 111 - HOLE MAKING CATALOG p185-310

USER GUIDE GUNDRILLS

Drill Penetration Instructions on Horizontal Pressure and Coolant Flow Rate for SUMOGUN
Milling and Lathe machines
Note: The following procedure (1-4) is recommended for Bar l/min
up to 400 mm hole depths using MNSNT ...-400... drill.
1 Drill a pilot hole 0.5xD deep with a short drill in 120 300
the same diameter as of the SUMOGUN drill. 110 275
2 Enter the pre-hole at slow speed, feed and 50 100 250
RPM until 1-2 mm before reaching the bottom.
3 Activate the cooling system and increase rotation speed 90 225
to recommended drilling speed, maintain for 2-3 seconds, 80 200
then continue at recommended drilling feed. No pecking 70 175
is required. Apply maximum possible coolant flow rate. 60 150
4 After having reached the required depth, reduce 50 125
speed to 50-100 RPM while exiting from the hole. 40 100
30 75
1 Pre-hole 1xD deep for centering 20 50
10 25
1xD
Ø10 12 14 16 18 20 22 24 26 mm
2 Slow rotation and feed while entering to the pre-hole
SUMOGUN DrillinSgUMRaOnGgUeN Drilling RangeDrillingDDriiallimngetDeirameter
1xD
Q l/min P bar
3 Maintain for 2-3 seconds and activate the cooling system
GUNDRILL Machines
Milling and Turning Machines

Gundrill Lubrication and Cooling

The best performance is obtained by using oil.
On equipment that uses water-soluble fluids (i.e.
machining centers and CNC machines) a concentration
between 10% and 15% is recommended.

Guidelines for Optimal Gundrill Performance

• Coolant pressure and flow
• It is recommended to use a strong coolant flow for

efficient chip flushing and cooling of the cutting edge
• Filtration: It is recommended to use a filter under 20 µm.
• Note: Improper filtration may result in interrupted flow of

the 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.

1xD

4 Continue drilling at recommended cutting conditions

SUMOGUN

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