My take on 440c,
440c is a widely used steel. It is one of the better performing stainless grades, and can be reliably heat treated although not as easily as straight carbon or alloy steels. It requires higher temps at longer soak times than carbon family steels, therefore it is more easily heat treated in a kiln than a forge. 440c can be sent out to be heat treated by most industrial heat treating facilities. High hardness can be achieved in 440c and the edge retention is good. Many high end art knife makers employ 440c because it is resistant to oxidation and makes for a beautifully polished piece that will resist tarnishing due to fingerprint oils. I used 440c strictly during the 1980's because I was a full time machinist and was allowed to include my blades in batches sent out to our heat treater. 440c also is relatively easy to work by conventional means as HSO mentioned, and is a relatively stable steel during the heat treat process meaning you can have it finished to 90% and not be too concerned about warpage. This is not the case with many carbon steels which are heat treated with less stock removed and finish ground after hardening and tempering. I suppose the question is what DEVINEGAN wants out of his knife. Does he need it to be stainless so that it can be left in a tackle box for a season without rusting away? Then 440c or any of the afore mentioned good stainless grades that JTW Jr. listed would be fine. Does he want to make a great inexpensive knife that will hold a keen edge for longer than average that he doesn't mind cleaning and oiling? If this is the case a straight carbon steel would be my recommendation. Like anything else in life stainless vs. carbon is a question of trade-offs & benefits vs. drawbacks. Either way I wish him well in his endeavor and would like to see what he comes up with.