I bought blades from HF for my Olfa cutter. The blades fit, but the hole in the center is round and when I cut through several fabric thicknesses the blade rolls. It rolls right over the fabric instead of cuttting the fabric. Works OK if I'm just cutting 1 layer of fabric. I'm glad I only bought a couple blades, because I won't buy anymore. Will just buy my blades when they are on sale, and sharpen them.