An adjustable securing device for securing spaced wedge members to provide for movement of the wedges together or apart comprises a threaded bore in one wedge that has threads opposite in direction from a threaded bore in the second wedge. A threaded member has threaded portions engageable with the threaded bores of the wedge members and upon engagement therewith, rotation of the threaded member in one direction moves the wedges apart while rotation in the other direction moves the wedges together. The wedge members preferably have tongues which fit complementary members, such as flanges, on blocks so that engagement of the wedge members with the blocks and movement of the wedges together or apart will either push the blocks apart or pull the blocks together.