A tool (100) for working the internal bore of a tube comprises a motor (10), having a housing with a rotary output; a housing sleeve (14a) and shaft (22); a first bearing housing (16), having a rotatably journalled first spindle (102), mounted on the housing sleeve; and an end sleeve and shaft connected to a tool head. The motor output drives, along a common axis (1), the housing shaft, first bearing spindle, end shaft and tool head. A change mechanism (56,58) is in the tool head to change direction of said drive to transverse said common axis. An output (60) is adapted to receive a tool bit. Gauge means (18,18′) is disposed on said tool head and is adapted, in use, to bear against the bore of the tube and maintain the tool head located radially with respect to the tube axis; and support means (24,24′) is disposed on one or more of said housing shaft, first bearing housing and end sleeve adapted, in use, to bear against the bore of the tube and support the tool. A long length of tool can work the inside of long tubes.