Description

What is Deep Hole Drilling

A deep hole is defined by its depth-to-diameter ratio (D:d), and typically holes greater than 10:1 are considered deep holes. Deep hole drilling into metal has a range of applications across several industries, with its origins tracing back to the need for straighter, more accurate gun barrels, and expanding as other industries integrated deep hole drilling processes to improve their own applications.

Deep hole drilling processes work by using special tools and setups to deliver high pressure coolant, evacuate chips cleanly, and achieve depth-to-diameter holes into metal beyond what a common CNC machine can reach. This allows manufacturers to achieve their manufacturing tolerances and production requirements reliably, accurately, and efficiently.

Deep hole drilling is generally performed on dedicated deep hole drilling machines which are manufactured and assembled to optimize the processes for straightness and efficiency. Advances in technology allow CNC machining centers, equipped with high pressure, through-spindle coolant, to be capable of gun drilling up to a limited depth-to-diameter ratio.

Deep Hole Drilling Process

Rotating Tool

• Typically used for non-symmetrical components, or round parts with off-center holes
• Cutting speed is determined by tool spindle speed
• Drill drift can be significant when compared to rotating work-piece, or counter-rotating process

Rotating Work-piece

• Typically used for round parts with a deep, on-center hole
• Cutting speed is determined by part, balanced to allow high rotating speeds
• Drill drift is reduced compared to rotating tool only

Counter-Rotating Tool and Work-piece

• Ideal process for round parts with a deep, on-center hole
• Cutting speed is determined by a combination of tool and work-piece rotation
• Provides optimal hole straightness and concentricity

APPLICATION