A tool assembly includes a first part, a second part, an operation member, two second tool units, and two first connection members. The first part has a first space, two first rails, two first engaging portions, two second spaces and two first connection portions. The second part has a head and a receiving portion which is insertion in the first space and includes receiving units for receiving first tools therein. Two second rails are formed on the second part and slidably engaged with the first rails. The operation member is connected to the second part. The two second tool units are pivotably connected to the two first connection portions and located in the two second spaces. The second tool units each have second tools which are pivotable about the first connection portion corresponding thereto. The first tools can be removed from the receiving units and connected to the operation member.