More about Deep Hole Drilling

Click here to find Deep Hole Drilling Manufacturers | Discuss Deep Hole Drilling & Other Topics

Deep hole drilling is typically performed using a gun drill, also known as a deep hole drill. Deep holes can be categorized as those whose depth is at least three times their diameter. The hole can be practically any length, although shank torsional rigidity and drill and machine design both factor into a system’s limitations.



To achieve precise holes, deep hole drills incorporate a number of specialized features, including specially engineered shank shapes, carbide cutting edges, and internally fed coolant systems. This coolant is sent to the cutting edges through the drill, and it helps the flute remain free of chips. The quality and accuracy of the hole drilled by a gun drill is directly influenced by a variety of factors, including the drill’s condition, the shank’s sharpness, and speeds and feeds used. Obviously, the nature of the work material, especially its consistency, is also a major factor during any machining operation.



An extensive range of materials can be machined with a deep hole drill, from metals like titanium and steel to ceramics and graphite. Some materials may necessitate certain shank shapes, speeds and feeds, and lubricants. Soluble oils are generally acceptable lubricants for most metal drilling applications, although this can vary depending on material; cast iron, for example, is typically drilled dry or using compressed air. Industries using deep drilled components include aerospace, construction, medical, manufacturing, hydraulics and military. The process was actually first used in the production of firearms, in which it was employed to create dependable, uniform barrels for guns and rifles.



Shanks in a gun drill are typically made from a heat-treated alloy. They are affixed to a steel driver and tipped with carbide, both joined using silver brazing. The tip features an off-center cutting edge that generates the proper pressure within the bore. This shank is held in the drill spindle, which is driven by a high-pressure pump. In certain applications, especially in extremely small holes, a solid carbide shank provides a more efficient drilling solution.