Abstract: Reference system for fixing a workpiece to a wire electric discharge machine with work table. The system consists of a base reference system attached to the work table (1) and forming a base reference surface (3) which defines a plane located on a level above the work table (1) but beneath the vertical working range of the machine and comprising two stop means (4, 5) to form the references defining the x- and y-directions of the plane. Moreover, a secondary reference system is included in the system which consists of fixed separate reference parts (10-12, 17-21) which at mounting on the base reference system, directly or as assembled outside the machine, define a fixed, desired and predetermined level within the vertical working range of the machine.

Abstract: A reference piece (30) for positioning a workpiece in a prescribed operational position, within the working zone (10) of a wire spark-erosion machine, relative to the cutting wire (8) of the machine, has associated with it at least one planar base reference surface (20, 22) formed on the mounting table (2) of the machine, outside the working zone, which base reference surface extends in an x-direction and in a y-direction perpendicular to the x-direction, and extends at the level, or in a plane, of the lower limit line (9) (base line) of the working zone with regard to a z-direction normal to the x- and y-directions.