An antiplane semi-infinite interface crack propagation problem has been considered, the crack tip coinciding with the angular point of the materials interface. The exact solution of the problem was obtained using the Mellin integral transformation. Asymptotic formulas for stresses near the crack tip were constructed, and they could contain one or two singular terms. To analyze the crack growth, the Novozhilov force criterion of fracture was used. Based on the obtained exact solution, the calculation accuracy of the crack angle and the destructive load, determined using asymptotics, was estimated. The dependences of these fracture characteristics on the composition parameters were investigated.