I use ultra smooth rods made by Ron Hock, maker of many fine woodworking accessories. They are 65Rc, 3/8" in diameter and about 6" long and the fit PERFECTLY into the slots of a Sharpmaker 203/204. They can be purchased on the internet at many vendors. Do a search on "Ron Hock", or "Hock" steels. If you have problems, let me know. They are $20-25 for a pair.