Abstract: A roller-reamer structure wherein for each roller shaft, the shaft is tightly, but releasably secured, both radial and thrust bearings being provided for relatively moving roller and shaft surfaces. The shaft is held in the various embodiments within accommodating slots by an interference fit between the shaft and the accommodating slot, by a partially slotted longitudinal opening that allows squeezing of a block about the shaft end, by a tapered shaft end being wedgedly held or by a slotted block opening and tapered wedging block member tightly securing the shaft. Some combinations include a sealed and protected self-lubricating reservoir.