Abstract: Conical tension failure in concrete is a basic failuremode for post-installed anchors in concrete components. Based on theoryof elasticity and the failure criterion of concrete, a theoretical formula for theultimate bonding capacity of expanding anchors is derived and simplified.Parametric analysis on the ultimate strength of the post-anchored concreteof different concrete strengths is carried out and it is found that theprojected diameter of the critical cone R is approximately a linearfunction of theeffective depth embedded in the concrete base for anchors. Compared withtest results, the predicted values of the ultimate tension capacity ofexpanding anchors by the simplified formula agree well with the testmeasurements from different sources, and the accuracy of the methodsatisfies the requirements of engineering practice.