Development of a drilling burr control chart for low alloy steel, AISI 4118

A control chart for drilling burr formation for low alloy steel, AISI 4118, was developed. A drilling burr control chart, based on experimental data, is a tool for the prediction and control of drilling burrs. High-speed steel split-point twist drills with different diameters were used for the tests. Burr classification was carried out based on the geometric characteristics, burr formation mechanisms, and sizes of the burrs. Four different burr types such as uniform burr (Types I and II), transient burr, and crown burr were found. New parameters consisting of process parameters and drill diameter were developed, and used to show a unique distribution of the burr types. Burr types and the resultant burr size showed great dependence on the new parameters regardless of the drill diameter. Through the chart, burr type can be predicted as a function of given cutting conditions. Also, cutting conditions that are believed to create preferred burr types can be selected.