A two-way fastener includes a first member threaded for being screwed into a first workpiece; a polygonal wall for receiving a tool to screw the first member into the first workpiece, the polygonal wall located at a base end of the first member; and a second member extending in an opposite fastening direction from the first member, the second member configured to be fastened to a second workpiece. A fastening method includes enabling the threading of a first member of a fastener into a first workpiece; and enabling the threading of a second workpiece to a second member extending outwardly from the first member and the first workpiece.