Abstract: A weldable pipe fitting includes a sleeve member of thermoplastic material, the sleeve member having a stress resistant portion of greater wall thickness, a terminal portion of greater wall thickness, and a fusion accommodating portion of lesser wall thickness between the stress resistant portion and the terminal portion, wherein the stress resistant portion is arranged in use to overlie the end of the pipe to be connected to the pipe fitting; the stress resistant portion of the sleeve has a standard dimensional ratio within the range of no less than 8:1 and no more than 12:1, the terminal portion of the sleeve has a standard dimensional ratio within the range of of no less than 8:1 and no more than 12:1, and the fusion accommodating portion has a standard dimensional ratio within the range of no less than 14:1 and no more than 19:1; and the internal wall of the sleeve is provided with an electric heating wire or wires along and within the wall and disposed circumferentially thereof adjacent the radially inne

Abstract: The invention provides a cutting tool for incising a helical cut around the internal surface of a hollow member comprising a tool carrier adapted for insertion into the hollow member adjacent the internal surface thereof to be cut; a cutting block carried by the tool carrier and adapted so as to be located, in use, within the hollow member, the block being freely pivotally mounted on the carrier about an axis normal to the axis of relative rotation, in use, of the carrier and the hollow member, and a cutting member secured to the cutting block and extending from the block generally parallel to the axis of pivot thereof upon the carrier, and being arranged such that, in use, as the tool moves (relative to the hollow member) in a helical path around the internal surface, the cutting edge of the cutting member moves (relative to the hollow member) in a direction generally towards the axis of the pivot of the cutting block on the shaft.