To determine the biomechanical characteristics of septal cartilage (SC) and costal cartilage (CC) taken from fresh cadavers using tensile testing and to establish CC graft material of a suitable thickness (ie, with tensile characteristics closest to those of SC).Grafts of varying thickness were harvested from the central part of the seventh-rib CC and SC of 18 fresh cadavers. Tensile testing was performed with a 0.5-kilonewton load calibrated at 7 mm/min. The results were shown as a force-elongation curve.No significant difference according to tensile force was observed between the SC group and the 1.0-mm and 1.5-mm CC groups (P = .09 and P = .32, respectively). However, a significant difference was observed between the SC group and the 2.0-mm CC group (P = .04). Although the strength value of the CC group was 5.03 MPa, the modulus of elasticity was 1.33 MPa. In the SC group, the strength value was 12.42, but the modulus of elasticity was 1.39 MPa. The strength value of the SC group was higher than that of the CC group (P = .001), but the modulus of elasticity value of the CC group was higher than that of the SC group (P = .001).From the standpoint of tensile testing for preparing columellar struts, 1.0-mm and 1.5-mm CC have similar characteristics to SC and thus can be used instead of it. However, it is important to determine the thickness of CC by considering the expected characteristics of the established material and the forces that affect the area in the nose where the graft will be placed.