rotation of the screw causing the lock nut fingers to flare out and engage the interior surface of a hollow wall or the circumferential surface of a bore in a solid wall application_number US 21410208 A description fig1 is an exploded view of the anchor 10 of the present invention fig2 is a side view of the anchor 10 of the present invention in the course of being installed to a hollow wall fig3 is a side view of the anchor 10 of the present invention fully installed in a hollow wall and fig5 is a partial end view of a finger of the lock nut assembly anchor 10 is of two piece construction having a nose piece 12 and a cooperative lock nut 14 nose piece 12 comprises a barrel member 16 of generally cylindrical construction having a truncated conical end portion 18 and a flange end 20 centrally disposed through both the flange end 20 barrel member 16 and truncated conical end portion 18 is a throughbore 22 formed about the circumference of barrel member 16 are a plurality of axial upstanding ridges 24 in parallel relationship with throughbore 22 formed on truncated conical end portion 18 are a plurality of slots or voids 26 which radiate from truncated conical end 23 towards barrel member 16 lock nut 14 is tubular in shape having a threaded throughbore 23 first end 32 of lock nut 14 is formed with a plurality of fingers 34 the number of fingers 34 being equal to the number of slots or voids 26 formed on truncated conical end portion 18 of nose piece 12 fingers 34 have a concave.