Hydrogenated acrylonitrile butadiene rubbers (H-NBR) were prevulcanized and their cure characteristics and physical properties were carefully investigated. The prevulcanization conditions, such as the temperature and time, were maintained identical to those used in the real manufacture of air tank. The minimum torque of the H-NBR compounds increased upon increasing the temperature and time, whereas the scorch time and cure time exhibited decreasing trends. The tensile green strength of each of them increased as a result of the increased gelation caused by prevulcanization. The tensile properties, such as the tensile strength, elongation at break, and tear strength, however, decreased. The 100 and 200 % moduli also decreased, while the hardness slightly increased. Unlike NBR 90-127 and NBR 100-149, which exhibited sharp decreases because of the formation of more non-optimally crosslinked points, the swelling resistance of the others decreased slightly, resulting in the decrease in crosslink density.