To improve the yield of a material by welding flat surface arc-like segments divided into arbitrary number in the circular direction after engage- connecting.

The segments 1A constituted from the flat surface arc-like segment parts 1A1 matching to the shape of a desired annular constituting member 1 and also, divided into the arbitrary number in the circular direction, U-shaped projections 1A2 formed at the front tip end surfaces thereof and reverse U shaped notching parts 1A3 formed at the rear tip end surfaces thereof. Successively, after arranging the prescribed number of the segments 1A and engage-connecting mutually the projections 1A2 and the notching parts 1A3, these engaging parts are welded and stuck. Therefore, the yield of the material is drastically improved in comparison with the conventional method of manufacturing the annular constituting member 1 by press-punching from one sheet. Further, the manufacture in the conventional equipment without needing an exclusive equipment can be executed.