Simply so, how good is n690 steel?
N690. The Bohler N690 is a widely popular blade steel, made by a massive range of companies. It's a very good steel and you can find some very nice knives with this steel at a reasonable price.
Beside above, is 304 stainless good for knives? 304 isn't a blade making steel so don't even try it, just be a waste of time. Order some good 1075/1080 from Adrimal Steel it isn't very exspensive. You can order from them on line. If you do choose to use a stainless steel, there are a several vendors you can send your blades to for heat treat.
Regarding this, what is 3cr14 stainless steel?
Martensitic stainless steel sheet 3Cr14Mo 3Cr14. Chinese made high carbon chrome steel 3Cr14Mo 3Cr14 is developed based on 420J2 by adding. chromium and molybdenum.
Is 316 stainless steel good for knives?
Austenitic grades such as 316 may occasionally be used for knife making, however, austenitic grades are generally not able to be hardened enough to ensure a lasting edge. There are also precipitation-hardening stainless steels that have excellent corrosion resistance and hardenability properties.