A method for injection moulding, comprising introducing, under pressure, a melt into a cavity (14) defined by two mould halves (10, 11) of a mould (6). The method is characterized by the steps of joining the mould halves (10, 11), for definition of said cavity (14), by moving at least one of the mould halves (11) along a first axis, and, by moving along a second axis extending transversely of said first axis, arranging a locking means (7) on the mould (6). The locking means (7) has locking surfaces (19) which grasp the mould (6) and its joined mould halves (10, 11), at least one locking surface (19) wedgingly engaging a complementarily designed surface (17) of the mould (6) to cause conversion of the force by which the locking means (7) is arranged on the mould (6), into a locking force for holding together the mould halves (10, 11) in their joined state. The present invention also concerns an injection moulding assembly as well as a mould for injection moulding assemblies.