<p>We study the problem of static loading of an elastic bimaterial formed by two half spaces and weakened by an internal circular mode-III crack. We analyze the case of perfect contact along the interface and the case of contact through a thin elastic compliant interlayer modeled by spring boundary conditions. The problem is solved by the method of boundary integral equations. We investigate the dependences of the static stress intensity coefficients in the vicinity of a crack on the contact boundary conditions at the interface, the ratio of material stiffnesses, the depth of the defect, and the thickness of the interlayer.</p>