For holding mechanical parts together, an elastic connector comprised of a base (1) for holding a S-shaped spring plate (2) and two symmetrical steel plates (35, 36), a supporting member (4) in said base (1) to support a rotary control member (5), two fixing rods (56, 57) to compress said steel sheets (35, 36) into U-shaped forms, a lid (7) sealed on said control member (5) at the top and secured in plate by two rivets (31, 32), wherein rotating a handle (62) on said control member (5) causes the two opposite ends of said S-shaped spring plate (2) to be moved outwards permitting an inserted rod member to be firmly retained to said S-shaped spring plate (2), and causes said steel plates (35, 36) to be returned to their original L-shape permitting them to laterally stop against said rod member so as to firmly retain said control member in position.