coupling 2 in the portion of the coupling shaft and in the portion of the center section table 4 lists dimensional values for a tool holder 1 with a steep cone shaft coupling not shown for a second shrink fit chuck length l 4 according to fig3 and to the detailed illustration in fig4 a groove 15 can be provided within the inner bore hole 12 in the tool holder 1 according to the invention which partially enlarges the inner diameter of the inner bore hole 12 in the form of indentations instead of one groove several grooves can also be provided after the shrink fitting of the tool shaft into the inner bore hole 12 has been performed the inner bore hole 12 is thereby not in direct physical contact with the tool shaft in the section of these grooves so that cavities are formed in these sections which advantageously receive humidity lubricants and similar adhering to the tool shaft so that no hydraulic supports can form between the inner bore hole 12 and the tool shaft which would hinder a complete torque transfer instead of several grooves for example extending in parallel or in radial direction relative to the axis a spiral shaped groove 15 can be provided this groove 15 does not only extend over the entire portion of the inner bore hole 12 but it ends at a distance a in front of the front end of the fit and.