Abstract: A method for making slots in metal pipe and, in particular, slots less than 15 thousandths of an inch in width. Firstly, providing a metal pipe (10) having an exterior surface (12) and an interior surface (14) which defines an axially extending interior bore (16). Secondly, cutting an axially extending elongate slot (18) having a width that is larger than desired in the pipe (10) with a cutting tool, the slot (18) providing fluid communication from the exterior surface (12) to the interior surface (14), the slot (18) having longitudinal peripheral edges (20). Thirdly, applying pressure to the exterior surface (12) of the pipe (10) along at least one of the longitudinal peripheral edges (20) of the slot (18) until the metal pipe (10) is deformed sufficiently to close the slot (18) to a desired width.