This video shows what chatter sounds like, and also what a stable cut sounds like. Chatter is the result of machining at a speed that is not stable for that particular combination of machine, toolholder and tool. BlueSwarf and Manufacturing Laboratories Inc. provided this video; these companies offers technology for identifying these inherently stable speeds for a particular setup. In the example shown, the chatter at 16,000 rpm limits depth of cut. However, finding a specific, inherently stable speed (in this case, 14,144 rpm) permits greater depth of cut. As a result, the slower spindle speed actually permits greater productivity.