I replaced the blades on my Craftsman 5 1/2" jointer that I bought on Craigslist. I got the blades by going to Sears Direct on the web. Get the model number of your jointer and plug it into your search engine. It should give you a list of vendors that carry replacement knives for it as well as the Sears Direct website. My replacement set cost about 12.95 plus 7.00 shipping. I installed the new set, then ground a new edge on the ones I took out, so now I have a spare set. You may also want to order some OEM replacement screws from the same source.