I appreciate all the information from everyone! So S35VN it is! One more question if ya'll don't mind... M390 and N690. Are these two any good or should I say any better than S35VN? The reason im asking is im looking for the ultimate edge retention and my Elmax does very good but I've heard people praise S35VN and im just trying to get at the truth before I blow several hundred dollars.
While I am not an expert on steel, I do own knives in all of the steels you have mentioned...M390 vs. S35VN & ELMAX are really different purposeful steels, so "better" is really a relative term. Depending on what you want to do with the knife and what traits you want in a steel, one may be better than another for your specific application.
M390 has very high wear resistance, exceptional corrosion resistance, and polishes up like chrome. It will hold an edge unlike most other steels, and even when cutting objects that are notorious for dulling knives. However, it is not as tough as ELMAX or S35VN.
N690 IMO is better compared with something like S30V, as it gives a nice balance of performance. It's a great steel although it is not super common in the States as it is not used on all that many production folders. However, many Knife Makers speak very highly of it and offer it as one of their steels.
If your knife is going to be used for general usage chores and not exceptionally heavy usage, I think you will really like M390, especially if you like thinner angles as it holds super thin angles very well. Quantifying how long an edge lasts is hard to, but my Benchmade 707 in M390 with an angle that is only about 13 degrees runs circles around the Benchmade 707's I own in 154CM, S30V, and D2, all on about a 19-21 degree angle. I would guess that for every one time I touch up my M390 707 that I would have to touch up the other steels my 707's are in four or more times. It's a very noticeable difference.
S35VN and ELMAX have excellent wear resistance, but it's not really comparable to M390 or S90V. These steels have excellent toughness and excellent corrosion resistance. For a knife that will see usage in which toughness is desired, S35VN and ELMAX are really great steels because they provide the toughness but without a tradeoff in other categories. In sum, those steels are just great performers across the board, and IMO that makes them a great choice for many different kinds of folding knives.
Another steel you may want to consider is CPM-154 taken to a high hardness (60-62 HRC). CPM-154 is a great performer and even at higher hardness levels it is a very, very tough steel (CPM-154 is 154CM steel prepared in a fashion that gives the CPM-154 superior performance that is nothing like 154CM). Like S35VN and ELMAX, CPM-154 gives great performance across the board, including notable toughness even at higher hardness. Above 61, CPM-154 has fantastic edge retention.
