When I started making there were few choices. 440C was what a lot of folder makers used as well as ATS-34. I am lucky to be able to play around with just about all the newest offerings and as such have a few favorites. SG2 is one of my first choices for a precision folder if cost is no issue. Super Cobalt from Takefu is another favorite however these alloys are very spendy and difficult to get. I still have a soft spot for Cowry-Y because it is a beautiful tight grained stainless that polishes like no other and holds a nice edge.
I use CPM-154 often and is my base line alloy of choice. However I am considering switching over to a new favorite BD1N from Carpenter. I have been a fan of nitrogen steels for a long time and until recently they have been both expensive and difficult to obtain until now. Carpenter decided after much prodding and pushing to make a nitrogen steel and I have had the pleasure of working with it for about 3 years now. I find the stuff pretty impressive and where most Japanese Nitrogen steels are 50-100.00 lb this new Carpenter BD1N is a fraction of that at around 7-8.00lb with better top end edge retention than CPM-154 with better corrosion resistance and similar toughness. Where it isn't quite SG2 in micro edge retention it is the best bang for the buck in the knife world from what I can tell.
A few of us who have been playing with it and testing it have shared it with other steel snobs and they were equally impressed.
I highly recommend trying it out and testing it for your selves.
