I bought the blades from my local Harbor Freight and I hate them. I bought the carpet cutter first and someone had stolen the extra blades out of the package.
I went back a couple of days later as they were expecting a shipment of the blades and picked up 3 packages (they only received 3) and exchanged the carpet cutter.
I used the blade in the carpet cutter first. There was only 1 extra blade, so thought someone had stolen the other. It skipped like crazy. I had to go over the edge 4 - 5 times in order for it to cut 2 pieces of material.
I exchanged the blade, thinking maybe someone had also put an old blade in the package when they stole the original.
I used a brand new package and it did the same thing. I don't know if I am having a run of bad luck or what, but I'll keep to the other blades for now.
Although these are a lot cheaper, I don't want to waste any more fabric!
Hope everyone else has better luck than I did!