Abstract: A spanner adapted for operative engagement with a hexagonal element, comprising a handle, jaws disposed at one end of the handle, the jaws defining first and second clamping surfaces and a contacting surface, the first clamping surface being continuous on one side of the jaws, the second, opposing clamping surface being disposed on the other side of the jaws, the second clamping surface being interrupted by a recessed portion which separates the second clamping surface into long and short clamping surfaces with the recessed portion being disposed therebetween, the contacting surface connecting the first and second clamping surfaces, whereby when the spanner is rotated in the clockwise direction the jaws engage the hexagonal element and when the spanner is rotated in the opposite direction, a protruding portion of the hexagonal element falls into the recessed portion, permitting the spanner to be repositioned for clockwise rotation.