Requirement deep hole drilling
For good hole drilling results, cooling, lubrication and high-pressure coolant systems are required.
Single flue gundrilling cannot only be achieved on deep drilling machines but is also very good on machining centers (drilling, turning and milling center) with:
• Deep-hole drilling oil,
• Emulsion (min. 10 - 12 % concentration, with additives),
• and under conditions, with a minimum quantity air/lubrication system.
The asymmetric goemetry single-edged single flute gundrill is nit self-starting, therefore a pilot hole or drill bushing is required.
Recommendation: Bushes DIN 179A medium
Important: Drill bushing has a form set against the workpiece
Recommendation: pilot drill with m7 tolerance
The prevent outbreaks during retraction of single flute gundrill we recommend a chamfer (X) of 60°.
Important: Too big difference between the tool and drill bush or pilot hole can cause the following problems:
• poor hole quality
• excessive hole straightness deviation
• drill breakage
Deep drilling machine
• Make a pilot hole
• Enter with stationary spindle or speed < 50 rpm
• Set coolant pressure, speed and feed
• Continuous drilling to depth without peck
• Switch off coolant supply after reaching hole depth
• Retraction with stationary or < 50 rpm
Important: Failure to comply may result in tool breakage.