Tapping fitting

Tapping fitting, suitable for application to a plastic pipe, comprising: a brass tap stem including a hollow main section defined by a housing wall, said housing wall having a plurality of recesses formed therein, the housing being attachable to a pipe; an internally-threaded insert mountable within the hollow main section, said insert having an upper most region defining a stop said insert further having protrusions formed on an outer surface thereof;
and a cutter assembly comprising a cutting blade attached to a non-deformable cutter body, the cutter body having an external screw thread and being mountable within the internally-threaded insert and axially moveable therein from a first position delimited by said stop to a second cutting position wherein the cutting blade engages the surface of a pipe to which the fitting is attached, said protrusions being deformable as said cutter is moved along said insert thereby deforming the protrusions into the corresponding recesses in said housing wall;