Used for removing rusted on nuts from studs etc A spanner is used to turn the hexagon end which has the effect of forcing the chisel end into a flat of the nut forcing apart without damage to the thread of the stud A spanner is used to turn the hexagon end which has the effect of forcing the chisel end into a flat of the nut forcing apart without damage to the thread of the stud Set of Four Size Range 9mm to 27mm