A retainer for holding a printed circuit card in a card rack or the like is disclosed. The retainer comprises a plurality of wedge-shaped members slideably mounted end-to-end on a rod, with at least one of those members being moveable in a transverse direction relative to the rod and to its respective adjacent members upon effective shortening of the rod to thereby bring a clamping surface of the transversely moveable member into contact with a printed circuit board and to apply a clamping force thereto. The rod is formed of an alkaline metal alloy that has been tempered to provide the rod with sufficient strength and decreased weight.