In this paper, we use the singular terms in Williams’ solution to quantify the behaviour at the edge of a complete (i.e. sharp edged) contact. To do this, we define two alternative parameters from the generalised stress intensity factors to bring out an internal length dimension from the solution. We then obtain an order of magnitude estimate of the extent of slip and/or separation when these remain near to the contact edge. When larger slip or separation lengths are implied, we derive only qualitative implications. Finally, we apply this analysis to an example problem.