A tube coupling sleeve (14) has a throughway (15) open at one end to receive an end part of a tube (11) to be coupled therein. The sleeve has an end stop (19) spaced from the open end to define the limit of insertion of the tube in the sleeve and an inner integral hollow spigot (20) extends along the sleeve from the end stop through the open end of the sleeve to project into the tube (11). The outer surface of the spigot has annular ridges or ribs (22) to grip the inner surface of the tube and hold it in place. The closed end of the sleeve (14) has an encircling head (25) to fit in a bore in a body and the head has an encircling steel star washer (27) to lock the head in the bore.
