Abstract
This paper describes characteristics of machining burrs generated inside the main hole at the intersection where cross holes are drilled, and the ball burnishing method to be employed to remove the burrs. The results obtained are as follows : (1) Both height and width of the burrs are small in the order, free-cutting steels, commercial aluminum, low carbon steel (SS400). (2) The generation of the burrs depends on the diameter difference between a main hole and an intersecting hole, and the feed rate at the end of drilling as well. (3) The burrs are decreased by the penetration of a crossed hole due to the moving chips inside the main hole. (4) The removal rate reaches 89 % for the leadedresulphurized steel, but it decreases down to 45 5 for the aluminum. (5) The direction of drilling as well as the rolling direction of work materials influence the burr formation and the deburring characteristics.
