Abstract: A hanger assembly for securing insulation or refractory linings to walls includes a circular stud which includes a flattened locking section of relatively short axial extent forming laterally projecting lugs, a somewhat less flattened anti-rotation section of substantial axial extent inwardly adjacent the locking section, and an unflattened or rotation section of short axial extent inwardly adjacent the anti-rotation section, whereby a quarter-turn retaining washer may be positioned over the stud to the rotation section, rotated a quarter turn and then moved outwardly along the anti-rotation section to engage and lock against the underside of the locking section.