Device and assembly for locking screwable elements

The invention relates to a device for locking a screwable element, comprising a ring part (82) and at least two locking sections (84) extending from the ring part (82). Each locking section (80) comprises a web (86) connecting the locking section (84) to the ring part (82) and having a web part with a predetermined curvature about and/or on which the locking section (84) is deflectable upon application of a compressive force from outside in the second plane, a pressure receiving section (90) for receiving the compressive force, and a hook-shaped end section (92, 94) which moves to an unlocking position when the locking section (84) is deflected under compressive force and returns self-adjusting to a locking position when the compressive force is not applied. Furthermore, an arrangement for locking a screwable element is proposed, comprising the device (80) for locking a screwable element, the screwable element (34, 36), and a snap-in device (38, 100) outside the device (80) and the screwable element (34, 36), which is associated with the hook-shaped end section (92, 94) such that the latter engages in a snap-fit manner into a recess (100) in the snap-in device (38, 100).