The utility model relates to a spanner tool technical field is a F spanner with adjustable, including handle, left arm, direction slot hole and adjustable right arm, the upper end of handle left end and left arm is fixed is in the same place, and the left part of handle is equipped with the direction slot hole of direction from top to bottom, is equipped with adjustable right arm in the directionslot hole, is equipped with the bracing piece on the handle on direction slot hole right side, is equipped with the screw on the bracing piece, and fixed mounting has the screw rod in the screw, and the left end and the adjustable right arm of screw rod are in the same place through pin fixed connection. The utility model has the advantages of reasonable and compact structure, convenient to use, the utility model discloses a left arm is the fixed arm, and the right arm is the adjustable arm of freedom, the right arm can be in the guide way back -and -forth movement, the distance between two arms can be adjusted through the screw rod, the utility model relates to a body instrument, it is convenient simple and direct, can be according to the size of valve, the distance of freely adjusting left arm, right arm can be used in the valve operating that the all size differs.