N-body calculations have shown that hard binaries play a dominant role in the evolution of small stellar systems. However, only one or two such binaries form by dynamical interactions and since the final components tend to be massive, their effect and observability in open clusters are limited to relatively short time-scales. In the present investigation we consider an initial population of binaries with physical evolution times exceeding the cluster age. These calculations may be applicable to a later phase when the heavier stars have suffered mass loss.