A tool structure includes a base, a first retaining member, a connecting rod, a second retaining member, and a threaded rod. The first retaining member is received in the base. The second retaining member is received in the connecting rod and engages the first retaining member so that the connecting rod is limited in the slot of the base. Thus, the connecting rod is rotated relative to the base to adjust different angles between the connecting rod and the base. In addition, the connecting rod has a first mounting hole and a second mounting hole so that the connecting rod is available for two kinds of screwdriver tips with different sizes.