The objective of the current investigation is to study the variation of Stress Concentration Factor in an unflawed Lug Joint that finds application in linkage structures or to complete the structural assembly in an Aircraft, so that the loads can be transferred from one structural member to another. Because when the loads are transferred from one structural member to another due to the pressure distribution on the Aircraft because of the service load, the stress concentration becomes so high that at the edges of the hole, there is a possibility that can initiate a minute crack. Suppose in case, if the crack gets unnoticed during Maintenance checks, then due to the service loads, there is a chance of the occurrence of Structural failure due to crack propagation that could cause a catastrophe. Hence it becomes important to investigate the Lug joints for Stress Concentration Factor.