Abstract: The refiner plate of this invention has a pattern of interlocking or nested elements having a "I"s "T"s, "S"s, "L"s, "F"s, "E"s, or "H"s shape which form channels. The body of the elements forms the refiner bars which hold the fibers as they move between the refiner plates in a disk refiner. The pattern of elements retarded the flow of fibers while at the same time providing a large open area for steam to pass through the refiner disks. The segments making up the elements producing a refiner bar which is reinforced for higher strength. The shape of the elements has a increased edge length exposed to the flow of fibers.