Abstract: A tool (1) is constructed for single use for making drill-holes in bones or removing cylindrical drill-hole cores from bones of the human body with a tubular tool body (2) which can be inserted into a receiving bore (8) of a tool holder (4). At least one cutout (5) in the tool body (2) and at least one protrusion (10) of the tool holder are coupled to rotationally affix the tool (1) to the tool holder (4). In the process, a flexible tongue (15) on the tool body (2) latches into an opening (16) of the tool holder (4) to axially fix the tool body. After the tool (1) has been used, the tongue (15) can be pushed out of the opening from outside, with plastic deformation, so that the tool can no longer be connected to the tool holder (4).

Abstract: A shaft sealing module is proposed for sealing a shaft which extends driving rotationally from a normal pressure chamber into a high vacuum chamber. It is essential for the shaft sealing module according to the invention that the dynamic seal of the shaft takes place not on the shaft itself but on a bushing mounted rotatably in a housing through which is guided a shaft and which is held on the shaft in friction connection, statically sealed, by elastic rings so that the bushing rotates with the shaft. The dynamic seal between the bushing and the housing is achieved by several radial shaft sealing rings which are preferably arranged so that between them is provided a prevacuum chamber with intermediate evacuation so that a two-stage dynamic seal is provided, where the prevacuum acts on the static seal between the bushing and the shaft in the sense of a gas penetration barrier towards the high vacuum chamber.