BTA Drilling Explained: Process, Tools, and Applications

I use BTA drilling for holes over about 20mm that need fast cycle times. When I need to remove a lot of material quickly and the diameter is large enough to support the tool, BTA drilling is my go-to process. It is also called single tube system drilling because the coolant flows around a single drill tube rather than through a double-tube arrangement like ejector drilling. BTA drilling — named after the Boring and Trepanning Association — is a deep hole drilling process for larger diameters. It’s the method I use when the hole is over about 20mm diameter and needs to be cost-effective. The process was developed in Germany in the 1930s and has been refined continuously since then. Modern BTA drilling machines can produce holes up to 300mm diameter and 20 meters deep. ...

June 11, 2026 · Engineer at the Deep Hole

What Is Gun Drilling? Working Principle and Applications

Gun drilling is a machining process for drilling deep holes with high straightness and good surface finish. It’s the method of choice when a hole needs to be deeper than a conventional twist drill can reach. The process gets its name from its original application: drilling gun barrels. The same principles used to drill a 5mm hole through 2 meters of steel for a rifle barrel are used today to drill cooling channels in injection molds, oil passages in crankshafts, and bores in hydraulic cylinders. ...

June 11, 2026 · Engineer at the Deep Hole