The ornamental design for a gripdevice for handlingwork pieces, as shown and described.
FIG. 1 is a front elevational view of a grip device for handling work pieces showing my new design, the rear elevational view being a mirror image thereof;
FIG. 2 is top plan view thereof;
FIG. 3 is a bottom plan view thereof; and,
FIG. 4 is a bottom front perspective view thereof.
The broken lines depict portions of the grip device in which the design is embodied that are not considered part of the claimed design.