284921 Tool holders and self-opening dieheads, for machine tools

28492110 Arbors, collets and sleeves for machine-tools and hand tools 28492130 Tool holders for lathes (excluding arbors, collets and sleeves) 28492140 Tool holders, self-opening dieheads and workholders of a kind used solely or principally for the manufacture of semiconductor boules or wafers, semiconductor devices, electronic integrated circuits or flat panel displays 28492150 Tool holders, n.e.c. 28492170 Self-opening dieheads for machine-tools and hand tools