Abstract: An aqueous solution (20) of an alkali hydroxide is stored and held in a tank (1). An electrode (5) is disposed in the tank (1), and a member (11) coated with a Ti-derived film is disposed in the tank (1) so as to be surrounded with the electrode (5). In this state, a power source (6) applies a negative potential to the electrode (5) and a positive potential to the member (11) to flow electricity between the electrode (5) and the member (11) immersed in the aqueous solution (20). Thus, the Ti-derived film coated on the surface of the member (11) is chemically removed by the aqueous solution (20).

Abstract: A bevel gear is generated using an annular milling cutter having a blade material made of a high-speed tool steel mounted to a main body, the blade material being coated with at least one layer of a film of a composition substantially comprising (Ti(1−x)Alx)(NyC(1−y)) (where, 0.2≦x≦0.85, 0.2≦y≦1.0), and dry cutting is performed at a cutting speed in the range from 20 to 400m/min without using a cutting oil. With this method, teeth can be generated at a greatly improved cutting speed without using any expensive tool such as cemented carbide, thereby realizing efficient production of a bevel gear at a reduced cost.

Abstract: A gear shaper effects a gear shaper cutting method by dry cutting, using a pinion cutter made of high-speed tool steel at a high efficiency. The pinion cutter of the gear shaper is coated, at least on the flank thereof, with at least one layer of film having a composition comprising: (Ti.sub.(1-x) Al.sub.x)(N.sub.y C.sub.(1-y) ), wherein 0.2.ltoreq.x.ltoreq.0.9 and 0.2.ltoreq.y.ltoreq.1.0. Gear shaper cutting is performed at a cutting speed of 300 m/min or less.