Abstract: A method includes a grinding step of forming the shape of a contact surface, a grooving step of roughening the shaped contact surface to form grooves therein, and a contact surface lapping step of lapping the contact surface having the grooves with a lapping film to form oil grooves for holding a lubricant oil. The surface roughness of the contact surface is such that the maximum height roughness Rz is 4 ?m or less, the mean length RSm of the roughness profile elements is 30 to 60 ?m, the skewness Rsk of the roughness profile is ?2.7 to ?0.6 (no unit), the reduced peak height Rpk is 0.09 ?m or less, and the reduced valley depth Rvk is 0.4 to 1.3 ?m.

Abstract: A method includes a grinding step of forming the shape of a contact surface, a grooving step of roughening the shaped contact surface to form grooves therein, and a contact surface lapping step of lapping the contact surface having the grooves with a lapping film to form oil grooves for holding a lubricant oil. The surface roughness of the contact surface is such that the maximum height roughness Rz is 4 ?m or less, the mean length RSm of the roughness profile elements is 30 to 60 ?m, the skewness Rsk of the roughness profile is ?2.7 to ?0.6 (no unit), the reduced peak height Rpk is 0.09 ?m or less, and the reduced valley depth Rvk is 0.4 to 1.3 ?m.

Abstract: At first step S1, a passivation film is removed by performing pickling on a separator for fuel cell and then a new passivation film is formed b performing heating at 200-280° preferably. At second step S2, mechanical polishing is performed on the horizontal top surfaces in the waiving portion of the separator for fuel cell, and a chipped portion is provided by chipping off a part of the passivation film. At third step S3, the separator for fuel cell is plated to form a first plating film composed of gold, rhodium, platinum or an alloy of two or more kinds of them starting at the periphery of the chipped portion. A complex ion stabilizer for suppressing dissociation of complex ions is added to plating bath.