Abstract: A tube squaring tool includes a housing having forward and rearward end areas and a tubular workpiece clamping device located at the forward end area for securing and retaining a tubular workpiece relative to the housing so that the end of the workpiece can be machined by a rotary cutting head carried by the housing and movable towards and away from the end of the workpiece by manipulation of a feed mechanism. The tubular workpiece clamping device includes a pair of saddle members carried within a saddle mounting ring with one of the saddle members being frictionally secured within the mounting ring using a detent mechanism and the other saddle member being movable relative to the mounting ring and the opposing saddle member by a threaded connector that enables clamping of a tubular workpiece between the saddle members when the moveable saddle member is moved in a clamping direction towards the opposed fixed saddle member.