In the inner chamber of a turbojet engine combustion chamber, each small black dot on the picture is a micro-hole that is inclined to the center of the cylinder. The material to be processed is nickel-based superalloy 4169 with a hole size of Ø 0.54 x 7mm and Ø 0.62 x 7mm. The number of holes in a single part exceeds 30,000.