Abstract: An improved seaming roller for use in automated canning machines to form seams between can lids and can bodies is disclosed. The seaming roller comprises a spindle mountable to the canning machine, a roller body rotatable about the spindle and having die surfaces for pressing against can lids to form seals, a pair of roller bearings to facilitate rotation, and a grease path for lubricating the bearings through the spindle. The seaming roller includes a positioner screw for properly positioning the roller body and bearings on the spindle such that the roller body can rotate freely without wobble and thus maintain the die surfaces in proper engagement to the can lids. A throughgoing bore is defined along the length of the spindle. The positioner screw is locked in position with a locking pin, inserted in the throughgoing bore and a locking screw which forces the locking pin against the positioner screw.