I have a 13" delta planer with disposable blades. I've found that it the ridgid, steel city and craftsman all use the same size blades. When I need new ones I've been getting them from Sears. It's the cheapest place I've found them and they cost around 25 bucks.
They are reversible and both sides of the blades have become dull. I know they aren't supposed to be resharpened. I thought I would try honing them and see if it made a difference before I went and got a new set.
I started by cleaning the blades. I then used some spray adhesive to glue some 600 grit wet dry paper to a 3/4 inch piece of mdf. I used wd 40 to lube the paper. I put the blades in a vice and honed the bevel by hand. I then placed the blade on a flat surface and honed the back of the blade. I did this to both sides. Man, did it make a difference. I ran a board through to test the cut and it was like a new set of blades.
I just thought this might help someone else.