Called DH at work and told him to stop and pick some up.
He called back and said there were only 4 packs. :(
Hopefully they'll get some soon.

As I said earlier. They cut on your mat the same as our other blades. And I have never had a cut that didn't heal itself to a certain point. They (mats) will not last forever even if they are self healing.

I know that some have looked for them in other stores or carpet places. But I noticed on the back of the package it said made exclusively for Harbor Freight

A lot of HF stuff is found only at HF. It's part of the charm of HF, unless you get committed to some tool that gets discontinued. And everything there is shipped from China, maybe they are bringing stuff from other countries now, but that's how HF got its name.

Our store had only 2 packs so I bought them and ordered more online as the store would not special order them, only told me they had more coming in this week. So I called this week and they are holding 20 packs for me to pick up on Monday. I tried the ones I bought and they work wonderfully. I cut thru 8, yes 8!! layers of quilting cotton fabric with only a second stroke to catch a few missed threads!!!! When cutting 4 layers, only one stroke was needed and there was minimal cutting into my mat. A bit less than with my other blade I'd say, because it needed less pressure.
The HF blades seem a little thinner than the Joann's blades, and I don't know yet how long they will last. But my son did a lot of cutting for me with the HF blade and it is still going strong.

I have cut 50 yards into 14" strips this week and it is still going strong.

Thanks, I wondered about that. Also thanks for the comment about your selfhealing mat being cut. Mine has a cut line as well. I thought maybe I had done something wrong

Don't forget!
You can also cut on the back of your cutting mat.
I have cut through one mat because I kept using the grid to cut on rather than using my ruler for placing cut lines.
The result was - - the most used lines got cut straight through!
If you use the ruler as your cutting guide (since they are designed to be used exactly in that manner), you can move the cuts around on your mat and avoid my problem <wave>

I got a card in the mail today saying HF received my on-line order for 20 blades - didn't say when they would be shipped, but also didn't say they're backordered. HF already sent an Email with the same info. Kinda makes me wonder why they bothered to send a card - kinda sounds like they ARE backordered, donchathink? If they have ANY profit margin at all, they're seriously cutting into it with BOTH an Email AND a card in the mail!

I tried my blade in my Fiskar's last night.
It worked great! Thanks for the tip. :D :D