Abstract: An apparatus for measuring a dimension of a workpiece includes a pair of rods positioned within a channel of a baseplate. At least one wedge member is mounted between the rods and forces the rods in a direction away from each other. A guide plate is adjustably mounted with respect to the baseplate, the guide plate having a cutout positioned at least partially over the rods for accepting the workpiece. A measuring tool is adjustably mounted with respect to the baseplate for moving in at least a linear direction.