To provide a shaft with serration capable of improving sticking property between a link member to be inserted and a fixing surface and also excluding necessity for increase of plate width and chamfering in the link member side.

In the shaft 10 in which the serration portion 17 is formed in an end portion of the shaft in order to connect with the link member to be inserted through in a rotation-restricting state and a fixing surface 15 having the diameter greater than the maximum diameter of the serration portion 17 and also arranging the fixing surface 15 fixing the link member when inserted through the link member is arranged in a starting end portion of the serration portion 17, a ring-shaped groove 16 is formed in the most internal periphery of the fixed surface 15, and the serration portion 17 is extended into the ring- shaped groove 16.