Five versions of the rectangular positioner have been designed and manufactured; the last one can be used in the plane machining of the milling machine with adjustable angles, especially the slotting of various angles of the Keel, the ribs and the crossbeam. At the same time, it can also be used as a precise positioning of rectangular assembly. The metal material can avoid the overflow of glue which makes the workpiece difficult to separate. The material is high hardness aluminum alloy (6061) an