In this paper, the feasibility to apply a closed fatigue crack as a substitute of a Stress Corrosion Crack (SCC) is investigated aiming at applications to ECT crack sizing. Several testpieces of closed fatigue cracks are fabricated, and ECT signals are measured after selected bending loads being applied to close the crack. From the measured signals, the crack profiles are reconstructed by using a deterministic inversion technique, and the sizing results are compared with the true crack profiles in order to evaluate the effect of crack closure. The results reveal that the closing load does not give significant influence on the crack sizing precision. Therefore, to simulate SCC with a fatigue crack closed by 3 point bending testing is not a suitable way from the view point of ECT inversion.