z_Deep-hole Drilling

Deep hole drilling (BTA or STS drilling, also known as Gun drilling) deepholedrilling was developed for drilling deep holes in steel in gun barrels, hence it is also known as Gun drilling. Armament manufacturing continues to be a common use of this process. Other common industries include energy, oil and gas exploration, engines, diesel fuel components, and plastic injection moulds. This process produces deep, straight holes in a variety of materials. A gun drill tool differs from a conventional twist drill by its unique head geometry. In this process of deep hole boring a fluid is pumped to the work-piece while the cutting head advances in the material. The high volume of fluid pushes the cuttings through the center of the tube and discharges out to a conveyor.

Originally a time-consuming and costly process, today’s technological advances make Deep hole gun drilling a highly efficient manufacturing operation in all metal cutting industries. With a standard twist drill it is difficult to maintain precision when the depth to diameter ration is very high. Gun drilling is an ideal solution for most deep and precision drilling projects. This high precision operation produces accurate, repeatable holes, with excellent surface finishes. Gun drills hold location to precise tolerances, are sized to exact specifications, produce burr free holes, and can be formed to produce specific shapes in blind holes with minimal machine adaptation. This process works extremely well in difficult to machine materials such as stainless steels, duplex alloys and heat-resistant super alloys. Holes deeper than 20:1 generally require a dedicated gun drilling machine to achieve highest productivity and process reliability.

Gun drilling

Quality Gun Drilling differs from the BTS/STS type of gun drilling due to the coolant entry and chip removal. Gun drills introduce coolant through a small hole within the tool, and chip removal occurs through a groove outside the tool. BTA drilling has fluid enter through a mechanism around the tool, while chips are evacuated through the drill itself.
With our specialized knowledge, we have been able to help customers design plausible and cost-effective solutions. Using the latest equipment available, we can handle an unusually large percentage of all gun drilling jobs. We can manufacture multiple hole types such as blind, stepped and thru holes to name just a few. MIR is capable of machining continuous holes from 32mm to 80mm (1.260 to 3.150 inch) diameter in solid materials up to 2 meters deep (80 inches). We are also capable of boring existing holes to sizes up to 150mm (6 inches).

Deep Hole drilling Drill Head Size’s available

MM Inch
31.75 1.250 new-32199_640
34.93 1.375
36.00 1.417
38.10 1.500
39.00 1.535
41.30 1.625new-32199_640
43.00 1.693
44.45 1.750
45.20 1.780
47.00 1.850
47.60 1.875
49.28 1.940new-32199_640
50.70 1.996
50.80 2.000
53.00 2.087new-32199_640
54.00 2.126
57.90 2.280
60.30 2.374
62.00 2.441
63.50 2.500new-32199_640
67.30 2.650
69.80 2.748
76.10 2.996
79.90 3.146
80.00 3.150