The elevated-temperature tensile properties of zirconium and of Zircaloy 2 were investigated and the creep properties were determined at temperatures up to 500 C. The effect of time at test temperature on the tensile strength of the 25 per cent cold-worked materials was investigated. The increased tensile strengths of cold-icorked zirconium and Zircaloy 2 were reduced to that of the annealed material by holding at 500 C for approximately 90 and 200 hr, respectively. Cold-worked Zircaloy 2 tested in creep had superior 1000-hr rupture strengths for all test temperatures, except 500 C, At 500 C, the 1000-hr rupture strength of the cold-worked material reverted to that of annealed Zircaloy 2 at the same temperature. The stress to produce a creep rate of 10 per cent per hr in the annealed Zircaloy 2 mas 25,000 psi at 150 C and 3200 psi at 500 C. Hydraulic-bursting tests also were made on seamless Zircaloy 2 and on welded zirconium tubing. The bursting pressures were considerably higher in the seamless tubes than in the welded tubing, 6800 psi as compared with 5400 psi at room temperature and 3150 psi versus 2200 psi at 400 C. The welded zirconium tubing failed at the longitudinalseam weld under hydraulic pressure.