Apparatus configured to deform a tubular work piece having a longitudinal axis, the apparatus comprising a support for supporting a tubular work piece to be deformed; rotation means for rotating the tubular work piece about its longitudinal axis; a nozzle for directing a stream of pressurized fluid at the tubular work piece in a direction transverse to the longitudinal axis of the tubular work piece; and means for moving one or both of the tubular work piece and the nozzle relative to one another such that the stream of pressurized fluid can be aimed at a plurality of locations along the tubular work piece; wherein the pressure of the fluid directed at the tubular work piece is great enough to cause deformation of the tubular work piece, but not so great that cutting of the tubular work piece can occur.