Head restrainer for immobilising the head of patients for producing NMR images such as those which are based on the application of electromagnetic beams (X-rays, gamma rays) and/or for carrying out surgical procedures, having a C-bend (1), at each end region of which at least one mandrel (3) is attached, these being substantially diametrically assigned with respect to each other, wherein at least one mandrel (3) is coaxially attached to an axially moveable bolt (2) which can be acted upon in the axial direction via a clamping device (11), and a force indicator (12) assigned to the clamping device, wherein fixing means (14) are provided which serve to temporarily set the bolt (2) and the attachment of the clamping device (11) and force indicator (12) to the head restrainer is releasable while the fixing arrangement is retained.
