Abstract: A pipe expander head and pipe expander is disclosed which comprises a housing 30, in which a pin 50 is mounted. The pin 50 has a tapered end 54 and is provided with a plurality of teeth 60. The teeth 60 mesh with a gear assembly 62, 66 and 68 which in turn are coupled to a handle 72. Upon rotation of the handle 72 the gear assembly 62, 66 and 68 is rotated to drive the pin to expand an expander head. The expander head includes a plurality of segments 39, 41, 43, 45, 47 and 49 which are coupled together with a circular spring 96. The expander head segments each include annular stepped expanding portions 72, 74, 76 and 78 and the stepped portions are provided with recesses 80 for accommodating a work piece to be expanded.