A pipe coupling which includes: • a male portion which in use is rigidly secured to one end of a first pipe , coaxial with said first pipe ; • a female portion which in use is rigidly secured to one end of a second pipe , coaxial with said second pipe ; • the male and female portions being sized so that the male portion is an easy sliding fit within the female portion when the first and second pipes are connected together; • the male portion being provided with a series of spaced keys protruding from the outer surface thereof; • the female portion being provided with a series of spaced keyways which are dimensioned and arranged so that the keys are a sliding fit within the keyways when the male and female portions are connected together; • at least one fastener, each of the at least one fastener including: • a male portion fitting rigidly secured to, or formed in, the male portion and providing at least one internally screw-threaded bore; • a female portion socket rigidly attached to, or formed into, the female portion , said female portion socket including a central aperture which is shaped to receive a plug therein, said female portion socket and said plug being radiused to match the radius of the female portion , and being substantially rectangular in plan; • a securing bolt dimensioned to fit in a corresponding fixing aperture formed in said plug , said securing bolt being releasably engageable with a corresponding bore; and • the male portion fitting is shaped, at least in part, to receive a portion of the plug ; wherein said plug is sized relative to the female portion socket such that the plug has a predetermined amount of movement relative to the female portion socket in either direction around the circumference of the female portion , even when each securing bolt present is engaged with the corresponding bore. • a male portion which in use is rigidly secured to one end of a first pipe , coaxial with said first pipe ; • a female portion which in use is rigidly secured to one end of a second pipe , coaxial with said second pipe ; • the male and female portions being sized so that the male portion is an easy sliding fit within the female portion when the first and second pipes are connected together; • the male portion being provided with a series of spaced keys protruding from the outer surface thereof; • the female portion being provided with a series of spaced keyways which are dimensioned and arranged so that the keys are a sliding fit within the keyways when the male and female portions are connected together; • at least one fastener, each of the at least one fastener including: • a male portion fitting rigidly secured to, or formed in, the male portion and providing at least one internally screw-threaded bore; • a female portion socket rigidly attached to, or formed into, the female portion , said female portion socket including a central aperture which is shaped to receive a plug therein, said female portion socket and said plug being radiused to match the radius of the female portion , and being substantially rectangular in plan; • a securing bolt dimensioned to fit in a corresponding fixing aperture formed in said plug , said securing bolt being releasably engageable with a corresponding bore; and • the male portion fitting is shaped, at least in part, to receive a portion of the plug ; <EOS>