Abstract: A breaker bar includes a mounting seat that has two support arms extending from a base portion thereof. The base portion and the support arms define a mounting space. The base portion has a first engaging section disposed between the support arms. Each support arm has a piercing. A connector has a head body and a second engaging section. The head body is rotatably disposed between the support arms in the mounting space. The second engaging section is connected to the head body, and is in contact with and rotatable relative to the first engaging section. A fastening member extends through the piercings of the support arms and the through hole, and fastens the connector head to the mounting seat.