A shank flange for use in a piano for supporting a hammer which makes a pivotal movement in response to depression on a key. The shank flange comprises a molding made of thermoplastic resin containing long fibers for reinforcement. The molding is molded by a long-staple method. The long fibers are carbon fibers. The shank flange excels in homogeneity and dimension stability, and has a high rigidity which can assure a smooth and stable action of the hammer. Also, dust and the like can be prevented from sticking to the shank flange and its surroundings, thus maintaining a precise action of the hammer and an aesthetically good appearance around the shank flange.