To measure fuel rod-centering forces exerted by double-acting springs assembled with different pairs of ferrules in a nuclear fuel bundle spacer, a gauge is provided to include an alignment rod and a probe carried by a handle for insertions into the ferrules of a ferrule pair. The alignment rod loads the side of the spring acting in its ferrule, while the other spring side exerts its fuel rod-centering force on a plunger mounted in the probe. The plunger is mechanically linked to a load cell which provides an electrical readout of the spring force.