A method of using a measuring and locating system utilizing a novel surface plate and fixtures associated therewith is disclosed. Basically, a plurality of uniform recesses are formed in a surface. At least one ferromagnetic member having an exterior shape corresponding to the shape of the recesses is placed in a recess and secured to a measuring and/or locating fixture. Magnetic attraction means are provided adjacent to recesses to aid in holding ferromagnetic members in place. The fixture may be easily removed by overcoming the magnetic attraction forces and replaced in exactly the same position. This method is useful for dimensional measurement of workpieces, locating workpieces for automatic machining operations, etc.