Solid Carbide Drills

1) Pilot/Pre-Drill Hole
• Drill: B976A… KC7315 or another drill
with a 140° point angle.
• Depth of pilot: minimum 2 x D.
• Drill Ø = nominal Ø up to nominal
+0,010mm (+.0004").
• Apply catalogue recommended
speeds and feeds.
2) Feed B27_ into Pilot Hole:
• Drill: B27_
• 1.000 RPM and recommended feed rate,
no rapid traverse.
• Depth: 0,25–0,30mm (.010–.012") above
the bottom of pilot hole.
Solid Carbide Drills
Application Recommendations
Recommendations:
• Use only a conical (B976A) or split-point drill to pilot
(do not use an SE-HP drill).
• Use a hydraulic chuck to achieve minimum tool
runout.
• Be sure the machine tool and setup are rigid.
• Check the pilot drill for wear. Excessive wear can
lead to premature wear on the B27_ cutting edge
and possibly catastrophic failure.
Recommendations:
The coolant channels of the B27_ are smaller than
typical Kennametal drills. Be sure that a steady supply
of coolant is delivered through the coolant channels
to the cutting edges. If coolant supply is not steady
or is unequal through both channels, check:
1. Coolant filtering system.
2. Sealing of adaptor/spindle.
3. Chips blocking the coolant hole on the drill shank.
NOTE: Reduce cutting speed to minimise imbalances in machine spindle/adaptor. On MQL applications,
make sure that the coolant is directly supplied from the chuck into the back end of the drill shank.
3) Drill Hole:
Cutting Parameters: start recommended
speed and feed rate at 0,25–0,30mm
(.010–.012") from the bottom of the pilot hole.
Recommendations:
DO NOT PECK OR DWELL up to 30 x D!
With long-chipping steel materials, it may be necessary
to increase feed rate by 10–20% to provide optimal chip
control. For long-chipping aluminium materials, it may
be necessary to decrease feed rate and increase speed.
Reduce feed rate on angled exits and cross holes
by 50–60%.
NOTE: Feed recommendations are usually higher than with conventional solid carbide drills.
4) Drill Retraction:
Cutting Parameters: 50 RPM and feed rate 2 m/min (40mm/rev or 1.6 IPR).
NOTE: Reduce cutting speed to minimise imbalances in machine spindle/adaptor.
www.kennametal.com G61
Solid Carbide Drills