Abstract: A sleeve and a concentric shaft having head at one end with a rectangular plate through with the shaft interposed between the head and the adjacent end of the sleeve. The plate initially is substantially V-shape and has the apex substantially parallel to a minor axis of the plate so that movement of the sleeve along said shaft towards the head deforms the plate from the V-shape into a substantially plainer configuration with the ends of said plate on a major axis of the plate extending laterally beyond the head. The present invention also embraces a method of fixing the anchor in a bore hole with the ends of the plate in an undercut in the bore hole and filling the bore hole with resin while venting air via a passage extending from adjacent to a closed end of the bore hole through a suitable cover.