Abstract: A cutting tool for a pipe of specific diameter comprises a generally cylindrical body (1) defining a central bore (10) extending along a predetermined axis. The body is divided into two axially spaced half portions (2A and 2B) which clamp between them a cutting blade (8) that projects into the bore (10). The body has a progressively narrowing slot (12) extending from its outer circumference to the bore. At the bore (10) the width of the slot (12) is narrower than the diameter of the bore. The tool to one side of the slot (12) is flexibly resilient so as to flex away when a pipe of diameter equal to the bore is pushed along the slot into the bore and to resile when the pipe has entered the bore and so urge the pipe against the blade so that subsequent relative rotation between the tool and pipe will cause the pipe to be severed.