The stress intensity factor variation along a semicircular surface law in a three dimensional solid (plate) of finite thickness is derived. This is done using a nested alternating procedure which employs the complete analytical solution for an arbitrarily loaded circular flaw embedded in an infinite solid. The method accounts for both the front-surface/backsurface as well as the boundary-crack interactions, as opposed to the method of Thresher and Smith (J. Appl. Mech. 39, 195-200, 1972) which considered only the boundary-crack interactions. In the present method, the residual tractions on the front and back surfaces, during the alternating procedure, are erased using Love's half-space solutions. Various numerical examples of tension and flexure loads are given. Results obtained by this method are compared with available experimental and computational data.