Abstract
The formation of burrs in face milling of plain carbon steel (S 45 C normalized to 179 HB) is investigated in connection with cutting conditions. Two types of burrs are observed. One is named a primary burr, which has the height nearly proportional to depth of cut. Another is a secondary burr, which is smaller than the primary burr because of separation of a tip of the burr during the burr formation process. Large depths of cut and small tool disengagement angles lead to the secondary burr formation, and cutting under these conditions can be one of methods for minimizing burrs. Although the component of cutting forces in the normal direction to the edge is thought to produce burrs, the measurement of cutting forces at the tool disengagement indicates that the component in the feed direction plays an important role in the secondary burr formation.