The invention relates to an electrical earthing nut (1). In the past these have sometimes vibrated loose, with the result that a failsafe safety device has been rendered inoperable. The invention overcomes this problem by providing a nut (1) that has a nut body (2) having an internal thread (4) to receive a threaded shaft and an external perimeter shaped to receive a tensioning device such as a spanner. Body (2) has opposing generally planar faces 5,6. Threaded apertures (7A, 7B, 7C) are p nut body to receive a bolt (8A) to secure an earth connector (8B) to the nut body (2) and grub screws (8C, 8D). F 9B, 9C, 9D) are provided on planar face (5) to scrape or cut into a surface against which the nut is to abut. Earthing used with a cable gland.