To provide an improved decorative cap and wheel nut or bolt assembly, and a method of assembling them.

An insert is coated and/or plated and includes a hex-shaped section and a section having a circular cylindrical outer surface. A cap includes a hex cross-section segment and a circular cylindrical cross-section segment. The hex cross-section segment of the cap slips easily over the hex section of the insert while the circular cylindrical cross-segment has a smaller inner diameter than the outer dimeter of the circular cylindrical insert section. The cap is formed of sheet material which is both plastically and elastically deformable. When pressed onto the insert, the cap deforms both plastically and elastically. An interference fit is formed between them by radial plastic deformation of the cap.