Our investigation of diamondlike-carbon (DLC) nanosprings with a 130-nm spring section diameter, which were fabricated by focused-ion-beam chemical vapor deposition (FIB-CVD), showed for the first time that nanosprings can be stretched. We observed large displacements of the FIB-CVD nanosprings in situ optical microscopy; in other words, the nanosprings showed behavior similar to that of macroscale springs. In addition, we investigated the dependence of the spring constant of the DLC nanosprings on the spring diameter. The spring constants, measured using commercially available cantilevers, ranged from 0.47 to 0.07 N/m. The diameter dependence of the measured spring constant could be accurately expressed by the conventional formula for a coil spring. The estimated shear modulus of the DLC nanosprings was about 70 GPa. This value is very close to the value of conventional coil springs made of steel. Furthermore, We measured the stiffness of the annealed nanospring at 1000 degrees C in vacuum. The stiffness was decreased to approximately half compared to the stiffness of the spring without annealing. (c) 2005 American Vacuum Society.