Abstract: A screwdriver includes a handle in which a chamber and a recess are respectively defined in two ends of the handle. An annular flange with a passage extends radially inward from an inside of the handle. A block and a spring are received in the chamber, and an impact rod with a spring mounted thereto is received in the recess. A tube extends from the handle and a shank is movably received in the tube so that on end of the shank contacts the impact rod and the other end of the shank contacts a bit engaged with a distal end of the tube. The block is pushed to compress the spring when the bit is pushed onto an object. When the impact rod drop into the dent, the block hit the impact rod and the bit exerts a sudden and large force to the object.

Abstract: A tool includes a base having a slot defined in an end thereof and a head pivotally engaged with the slot. An output shaft extends from the head and a recess is defined in an end of the head. A tube extends from the base and a shank extends through the tube. An eccentric rod extends longitudinally from the shank and is located in the slot and is retained within the recess. When rotating shank, the head is rotated about the output shaft by the movement of the eccentric rod.