Abstract: The present invention relates to a process for the preparation of a product of blood coagulation factors II, VII, IX and X which is virtually free of virus, the process comprising heating an aqueous liquid containing these factors in the presence of calcium ions and a chelating agent and, optionally, an amino acid, a saccharide or sugar alcohol, antithrombin III and/or heparin. The product can be used for the treatment of blood coagulation disorders.

Abstract: A chuck for rotary tools with a cylindrical chucking shank encloses such shank with a basic body. A radial through-hole in basic body serves to receive a clamping screw which applies pressure to a clamping member which is seated inside a through-hole between the clamping screw and chucking shank. A clamping member is provided with a radial projection and the through-hole with a cross-sectional narrowing along its inner end. In between the radial projection and the narrowing is an elastically compressible spring element which, due to its return force, lifts the clamping element away from the chucking shank and pushes it back into the through-hole when it is not under tension from the clamping screw.