How to Manage Chip Control in Drilling

Chips can be a frustrating challenge in deep-hole drilling, as they are a source of breakage and poor finish quality. There are many ways to deal with this issue, but they all rely on effective chip formation and evacuation, as well as consistent and measured application of coolant to the work interface.

Peck cycles, which pause the drill to allow time for chips to be evacuated before the cutting edge continues the machining cycle, can be effective in certain applications. However, these back-and-forth peck cycles can reduce tool life and increase the likelihood of breakage.

Choosing the right flute shape, point geometry and coating combination for the material and application is critical to effective chip control. This requires a thorough understanding of the material, hardness, hole tolerance, number of holes, presence of cross-holes and surface finish requirements.

Feed rates are also crucial for controlling chip formation. Too low of a feed rate will cause the machining material to build up on the hone and primary rake, altering the chip behavior.

The staggered distribution of teeth in the BTA drill and the design of chip breakers on the rake face of each tooth improves the bending deformation of chips and assists with breaking them, so that the shaped chips have a profile size that can be easily evacuated. This method has the potential to improve the machining quality of deep-hole parts and decrease the number of breaks that occur.