To provide a tooth contact sound control gear which can prevent the exfoliation of a tooth part certainly with small tooth contact sound.

The tooth contact sound control gear comprises a gear-shaped core part 51 and a tooth part 52 having a tooth face 52a at the tip of radial direction which is prepared on the peripheral part of the core part 51 over the whole circumferential direction. The tooth part 52 is made of the resin layer 53 made of the resin of a uniform composition. The bulk specific gravity of the resin layer 53 becomes small as approaching the tooth face 52a. The bulk specific gravity of the resin layer 53 is good as it becomes small continuously according to approaching the tooth face 52a. Preferably, the foaming ratio of the resin layer 53 becomes large according to approaching the tooth face 52a.

COPYRIGHT: (C)2010,JPO&INPIT