Hand tool assembly

A hand tool assembly comprising:

• a cylindrical first body having a first connection portion on a first end thereof, multiple first grooves defined in an outer periphery of the first body;
• a driving head connected to a second end of the first body and having a non-circular mounting hole, an engaging slot defined in an inner periphery of the mounting hole, a positioning member engaged with the engaging slot;
• a cylindrical second body extending through the mounting hole, a sixth connection portion and a seventh connection portion respectively formed on two ends of the second body, a fifth connection portion formed on an outer periphery of the second body and located at a middle portion of the second body, the fifth connection portion engaged with the mounting hole, the fifth connection portion having a second groove, the positioning member engaged with the engaging slot and the second groove, and
• a handle unit having a handle, a control member and at least one engaging member, the first body extending through a axial penetrating hole of the handle, wherein when the handle moves to a first position relative to the first body, the control member moves to a second position relative to the handle, the control member pushes the at least one engaging member to be engaged with one of the first grooves to position the handle to the first body.