Abstract: A threaded fastener (1) is disclosed for anchoring into a substrate comprising a core portion (2) having at least one helical continuous thread provided along a substantial portion of the length of the core, in which the helical thread has a substantially V-shaped cross section defining two flanks (4a, 4b) which subtend an angle of between substantially 60° and 90°, and the thread has a helix angle of between approximately 20° and 45°. The crest of the thread may be flattened, and the fastener (1) is especially suited to anchoring to a masonry substrate.