An anchor nut, is a type of self-locking nut,. Anchor nuts are used in blind applications where access to the other side of the structure being joined is limited. The upper threaded portion of the nut is deformed out of round. This provides the locking function as the threads of the screw or bolt bind tightly with the nut threads. Anchor nuts are offered in one-lug, two-lug, short-lug, corner or right angle body configurations. A floating assembly version provides flexibility when installing the bolt or screw. Fixed, miniature and countersunk body, versions are also available. Deep counter bore versions have an extended smooth portion of the shaft before the threaded portion. Self-aligning, spring-loaded or replaceable nut, versions are also offered. Self-sealing anchor nuts have either rubber, silicon rubber, or fluorosilicone rubber inserts.