Abstract: A louver system is described incorporating louvers having a rectangular outline and incorporating notches on each of the shorter sides of the louver. A one-piece molded hinge pin assembly is provided with a cylindrical extension to act as a hinge pin when the assembly is mounted on the louver. A pair of assemblies are secured to opposite sides of the louver by inserting the bodies of the assemblies into the notches provided therefor in the louver. Each assembly includes a slot into which the sheet metal, of which the louver is formed, is inserted while the cylindrical extension of each of the assemblies extends outwardly from the sides of the louver to provide a hinging axis upon which the louver may be supported and rotated. A detent or hole is provided adjacent each of the notches to accomodate a locking pin molded as part of the assemblies. When the assemblies are inserted into the notches, the locking pins engage the detent or hole to thus secure the hinge pin assembly to the louver.