A structural post includes a base plate defining a plurality of through holes, and a post portion that includes at least a pair of internal walls and at least a pair of external walls. A connector block is configured to receive a locking screw and to engage with a bolt thread of a bolt. A lock plate has a plate thread that is configured to engage the screw thread of the locking screw, and the lock plate is configured to expand upon being drawn by the locking screw into tight engagement with the connector block. The expanded lock plate is configured to apply a force on one of the pair of internal walls and one of the pair of external walls.