The Single Flute Gundrill is a general-purpose drill used to drill virtually any material not in excess of 50 Rc. The gundrill is a self-piloting tool, which requires high-pressure coolant flowing through the tool to keep the cutting edge lubricated. Consequently, supplying a thin film of lubrication on the bearing pads allows for ample chip evacuation.

The design of the Single-Lip, straight deep Vee flutes and High-pressure coolant allows for a fast consistent penetration without the need for pecking. The tool can achieve precision holes in one pass thus eliminating the need for secondary operations.

Due to the point not being on center, the tool requires a starter bushing to enter the material. It is always recommended that the bushing make contact with the part. The bushing I.D. tolerance when new is +.0002" -.0000" and is usually discarded at .001" over the drill size.

CNC Machining Center applications require a pilot hole to serve as a starter bushing. We recommend that you produce a hole +.0005" in diameter and two times tool diameter in depth. A flat bottom configuration is preferred.

The advantages of this type of tool are:

• Drill any diameter from the solid.
• Obtain bottom configurations on blind holes without secondary qualifying passes.
• Straightness tolerances of 001" per foot.
• Concentricity tolerances of .001" per inch or better.
• Hole diameter tolerances of +/- .0005".
• Finishes tolerances as low as 4 Ra.
• Burr free intersections.
• Consistent reproduction from hole to hole.

Design Features of the Single Flute Gundrill

Contours/Wear Pads give the tool the burnishing effect needed to obtain the finish and hole size while controlling the heat/friction for a given material. They are strategically engineered per application down the length of the outside diameter of the carbide. Geometry plays the most instrumental part of the equation. The proper selection and reproduction of the geometry is crucial to its total overall performance. Every material has its own machineability characteristics which require the inside angles, outside angles, oil clearance angles and clearances in general to be engineered to custom fit to each application. Coolant Holes are offered three ways: