I haven't had the opportunity to try out the Harbour Freight blades. I just bought the sharpener for the OLFA rotary blades and have been relatively successful with sharpening the old blades. They won't last as long after being sharpened, but they do work again...not sure how many times I can sharpen them, but will let you know when I find out. I did check with the two HF stores that are in our area...over 60 miles away....and they look at me like "deer in headlights".