How to Handle Interrupted Cuts in Deep Hole Drilling
What Happens at an Interruption Interrupted cuts in deep hole drilling happen when the drill passes through a cavity, cross hole, keyway, or any gap in the material. The cutting edge hits the far wall of the cavity, loses contact, and then slams back into the material on the other side. That shock loads the edge and chips it. I have seen a sharp C2 carbide edge chip on the first interruption of a 10mm hole through a valve body with a 6mm cross hole. The chip happened in the first 0.1 seconds of re-entry. After that, the drill was cutting with a damaged edge and the bore finish was shot. ...