If you're looking for replacement blades that will last about three times as long as your stainless steel blades, then look no farther than the OLFA Black Max Replacement Blades. You can use these Black Max breakaway blades with your OLFA Breakaway Steel Knife. These blades are sharper than stainless steel, however they can scratch glass if you're not careful. One package includes 50 breakaway blades.