440
440 steel (440A or 440B) is higher quality steel compared to 420. 440 stainless steel is also used especially for knives of lower price category. Slightly better edge holding ability and wear resistance than 420, as 440 series steels achieve higher hardness - usually from 55 to 59 HRC. Carbon content 0.65-0.95%. If the knife producers mentions 440 steel, it usually means 440A steel.
Steel composition (440A): 0,65 - 0,75% Carbon, 16 - 18% Chromium, 1% Manganese, 1% Silicon, 0,75% Molybdenum, 0,04% Phosphorus, 0,03% Sulfur