7 Clamping devices for machine tools, namely, three jaw chucks, collet chucks, stationary chucks and their parts, arbors, mandrels, clamping bushings, collets and their parts; feed fingers on machine tools, and their parts; bar guidances for bar-fed work-pieces on machine tools; machine tool accessories, namely, changing fixtures for tools, and their parts; machine tool accessories, namely, handling devices for work-pieces, and their parts