A plastic, undetachable anchor (10) to affix a component (52) to a support (54), comprising a rectangular affixing aperture (56), the anchor comprising a resilient, flange-like head (12), a hollow shank (16) subtending an axis and connected at one end to the head (12) and receiving an affixation screw (20), further resilient detent arms (40,42) connected to the shank end away from the head (14), where the detent arms (40,42) running obliquely outward toward the head (14) are fitted at their free ends with a detent shoulder (44) engaging { in the assembled state - an edge of an affixation aperture (56) facing them in order to secure the anchor (10) against being pulled out of the affixation aperture (56).